Final Examination

Physics 1050 - Fall 2014 - Final Exam - Posted Version

Problem 1:
When you stand in front of an open refrigerator, trying to decide which flavor of Ben and Jerry's to eat, you feel cold even though no chilled air actually touches your skin. The reason you feel cold is that
(A) the cold refrigerator is radiating cold toward you and is lowering the temperature of your skin directly.
(B) you can sense the presence of nearby cold air, even though it is not exchanging cold with your skin.
(C) you are radiating heat toward the refrigerator but receiving relatively little radiated heat in return.
(D) you can sense the presence of nearby cold air, even though it is not exchanging heat with your skin.
Problem 2:
You are visiting a playground and you notice that a girl on one swing completes each full cycle of motion in much less time than a boy on another swing. The girl has a much shorter period of motion (time between cycles) than the boy because
(A) the girl is much lighter than the boy.
(B) the girl is riding on a much taller swing than the boy is riding.
(C) the girl is much heavier than the boy.
(D) the girl is riding on a much shorter swing than the boy is riding.
Problem 3:
You are standing in the middle of a level subway car that is moving forward at constant velocity when another passenger accidentally spills an enormous container of olive oil. Suddenly, the floor cannot exert any frictional forces on your feet. Because nothing else is touching you, you
(A) shift toward the back of the subway car (opposite its velocity).
(B) remain in the middle of the subway car.
(C) shift toward the side of the subway car (perpendicular to the direction of its velocity).
(D) shift toward the front of the subway car (in the direction of its velocity).
Problem 4:
You are eating at an outdoor restaurant on a cold day and the restaurant has a red hot heating element positioned about 10 feet above you that keeps you surprisingly warm. Heat from that element reaches you
(A) primarily via convection and conduction, with almost no heat flowing to you via radiation.
(B) equally well via conduction, convection, and radiation.
(C) primarily via radiation, with almost no heat flowing to you via conduction or convection.
(D) primarily via convection and radiation, with almost no heat flowing to you via conduction.
Problem 5:
Just mixing gasoline and air together won't make them burst into flames because
(A) their densities must be increased considerably before they will ignite.
(B) they must be compressed into liquid before they can burn.
(C) their velocities must be increased considerably before they will ignite.
(D) something must provide the activation energy needed to initiate the chemical reaction.
Problem 6:
A juggler tosses a club straight up. Disregarding any effects due to the air, what force or forces are acting on the club while it is above the juggler's hands?
(A) Its weight along with a steadily decreasing upward force.
(B) Its weight along with an upward force that steadily decreases until the club reaches its highest point. After that point, there is only the constant downward force of gravity.
(C) Its weight.
(D) A steadily decreasing upward force from the moment it leaves the juggler's hands until it reaches its highest point and then a steadily increasing downward force as the club returns toward the jugglers hands.
Problem 7:
Wrapping a hot potato in aluminum foil helps keep the potato warm because the shiny aluminum foil is
(A) a very poor emitter of thermal radiation.
(B) a poor conductor of heat, so the surface temperature of the foil is much less than the surface temperature of the potato.
(C) so thin that it doesn't have enough mass to cool the potato significantly.
(D) actually transparent to infrared radiation and allows radiant heat from the room to enter the potato and keep it warm.
Problem 8:
To transform 1 kilogram of boiling-hot water at 100 °C into 1 kilogram of steam at 100 °C, you must
(A) allow the water to boil for more than 5 minutes, although it doesn't require any additional heat.
(B) add a large amount of heat to the water.
(C) allow the water to boil for less than 5 minutes, although it doesn't require any additional heat.
(D) remove a large amount of heat to the water.
Problem 9:
Flowing honey is less likely to become turbulent than flowing water because
(A) honey's larger viscosity favors laminar flow.
(B) honey's larger density favors laminar flow.
(C) water's larger pressure favors turbulent flow.
(D) water's larger viscosity favors turbulent flow.
Problem 10:
Water is flowing gently out of the end of a garden hose. You block off most of the hose's opening with your thumb and now the water sprays out at high speed because you
(A) are keeping air from getting into the hose and reducing the water pressure.
(B) have reduced the water's speed in the hose so that it wastes less of its ordered energy.
(C) are doing work on the water with your thumb and greatly increasing its ordered energy.
(D) are compressing the water and increasing its density.
Problem 11:
The first kind of perpetual motion machine provides an inexhaustible supply of mechanical work (or the equivalent of work), but consumes nothing at all from its environment, not even heat. An example would be a black box that consumes nothing yet provides electricity forever. This form of perpetual motion machine is impossible because it
(A) violates the law of conservation of momentum.
(B) violates the law of conservation of energy.
(C) violates the law of thermal equilibrium.
(D) violates the law of entropy.
Problem 12:
A seemingly "haunted" house emits creaking sounds as it cools off at night. Since sound carries energy, the house must obtain that energy from somewhere (other than ghosts and goblins). While this energy begins as thermal energy, the sound doesn't appear until the outside temperature drops well below the temperature of the house because
(A) sound, like heat, can only flow from hotter objects to colder objects.
(B) the house's thermal energy can only become work and sound as heat flows from the hotter house to the colder outside air.
(C) building materials become too soft during the day to vibrate with enough efficiency to convert thermal energy into sound energy.
(D) the house's thermal energy increases most rapidly after dark.
Problem 13:
When a liquid flows through a collection of stationary obstacles, its flow can be smooth and laminar, or it can be swirling and turbulent. The liquid's flow is more likely to become turbulent if you increase its
(A) pressure.
(B) transparency.
(C) viscosity.
(D) speed.
Problem 14:
Moments before it's ignited by the sparkplug, the mixture of fuel and air inside an automobile engine cylinder is compressed to very high density. During the compression process, the mixture's
(A) temperature stays the same but its pressure rises.
(B) temperature rises dramatically but its pressure drops.
(C) temperature rises dramatically and so does its pressure.
(D) temperature drops dramatically but its pressure rises.
Problem 15:
The hotter it is outside, the more electric energy an air conditioner must use to remove each joule of heat from the 72 °F indoor air in your home. It must consume more electric energy on a hotter day because
(A) delivering that joule of heat to the outdoor air creates less entropy as the outdoor air gets hotter.
(B) entropy flows into your home faster when the outdoor air is hotter.
(C) heat flows into your home faster when the outdoor air is hotter.
(D) delivering that joule of heat to the outdoor air creates more entropy as the outdoor air gets hotter.
Problem 16:
You are pulling your niece uphill on a sled and the sled experiences a small downhill frictional force as it slides uphill on the snow. Your niece is traveling in a straight line at a constant speed. The net force your niece is experiencing is
(A) in the uphill direction.
(B) in the downhill direction.
(C) zero.
(D) in the upward direction.
Problem 17:
You wake up one very cold winter morning to find the grass outside covered with frost. How did this ice form on the grass?
(A) Water molecules from the moist air landed on the cold grass more frequently than they left the grass, and there was a net accumulation of water molecules as ice.
(B) Heat from the warmer air became ice as it flowed to the colder grass
(C) Water that normally evaporates from warm grass as water vapor instead evaporated as ice from the cold grass.
(D) Heat from the colder air became ice as it flowed to the warmer grass
Problem 18:
You throw a curve ball that is bending toward your right as it travels away from you. It is able to bend in this manner because
(A) it is deflecting the airflow around it toward your left.
(B) it is deflecting the airflow around it toward your right as well.
(C) you gave it a rightward push as it came out of your fingers.
(D) the pressure in front of it is higher than the pressure behind it.
Problem 19:
You are rearranging your room and are now sliding your desk across the floor at constant velocity. Which of the following statements about the forces acting on the desk is correct? [Consider only horizontal forces.]
(A) The amount of force that you're exerting on the desk must be equal to the amount of its weight.
(B) The amount of force that you're exerting on the desk must be more than the amount of its weight.
(C) The amount of force that you're exerting on the desk must be more than the amount of force that friction is exerting on it.
(D) The force that you're exerting on the desk must be equal in amount but opposite in direction to the force that the floor is exerting on it.
Problem 20:
You make a sharp left turn in your car and your cellphone slips off the dashboard and out the right passenger window. The cellphone leaves the car because
(A) the car did not exert enough leftward force on the cellphone to make the cellphone accelerate with the car.
(B) the dashboard of the turning car tilted sharply to become a ramp and the downhill ramp force pushed the cellphone out the window.
(C) the car exerted a rightward centrifugal force on the cellphone that pushed the cellphone out the window.
(D) the cellphone's weight pulled the cellphone out the window.
Problem 21:
As the water stream from a fountain rises upward in the open air, its gravitational potential energy increases,
(A) neither its pressure potential energy nor its kinetic energy change.
(B) its kinetic energy decreases, but its pressure potential energy remains constant.
(C) both its pressure potential energy and its kinetic energy decrease.
(D) its pressure potential energy decreases, but its kinetic energy remains constant.
Problem 22:
You are tossing popcorn straight up and catching it in your mouth. At the moment each piece of popcorn reaches its peak height, its velocity is
(A) zero and its acceleration is downward.
(B) downward and its acceleration is zero.
(C) zero and its acceleration is zero.
(D) downward and its acceleration is downward.
Problem 23:
At high altitude, a commercial jetliner must compress the outside air before circulating it in the pressurized cabin. The compressed air must first be sent through an air conditioner, however, because compressing air
(A) turns it into a liquid and the air conditioner's evaporator allows it to return to a gas.
(B) decreases its humidity.
(C) increases its humidity.
(D) increases its temperature.
Problem 24:
As an orchestra warms up, the wind instruments (e.g., flutes, clarinets, oboes) and the air inside them actually become hotter. These instruments have openings and are not sealed. How does this warming process affect the average pressure and density of the air inside the wind instruments?
(A) The average pressure does not change, but the average density increases.
(B) The average pressure increases, but the average density does not change.
(C) The average pressure does not change, but the average density decreases.
(D) The average pressure decreases, but the average density does not change.
Problem 25:
You are cleaning the siding on your house by spraying water at it from a hose and nozzle. At the center of the stream of water, right where it hits the siding, the water is coming to a complete stop. The pressure in the water at the center of the stream as it touches the siding is
(A) lower than atmospheric pressure, but more than zero.
(B) higher than atmospheric pressure.
(C) equal to atmospheric pressure.
(D) exactly zero.
Problem 26:
A rigid two-blade wind turbine that is experiencing zero net torque
(A) has a constant angular velocity, which may be zero.
(B) is motionless and horizontal.
(C) has an angular velocity that is gradually decreasing toward zero.
(D) is motionless and may be horizontal or tilted.
Problem 27:
You and your friend carry identical water bottles from the first floor to the fifth floor. You start side-by-side and you finish side-by-side, but one of you uses the stairs while the other climbs straight up a ladder. Which of you did the most work on your water bottle?
(A) Neither. You both do the same work on the water bottle.
(B) The person who uses the stairs does the most work on the water bottle.
(C) The person who climbs the ladder does the most work on the water bottle.
(D) The person who takes the most time to reach the fifth floor does the most work on the water bottle.
Problem 28:
Ice cubes gradually shrink in a frost-free freezer because
(A) the ice melts periodically and some of it evaporates before it can refreeze.
(B) the ice melts periodically and some of it drips into the bottom of the freezer.
(C) the freezer mice like to nibble on the ice cubes.
(D) water molecules go directly from solid ice to gaseous water vapor.
Problem 29:
As heat flows from hot soup to a cold kitchen, the entropy (disorder) of the soup
(A) decreases, the entropy of the kitchen increases, and their combined entropy remains unchanged.
(B) increases, the entropy of the kitchen decreases, and their combined entropy increases.
(C) decreases, the entropy of the kitchen increases, and their combined entropy increases.
(D) increases, the entropy of the kitchen decreases, and their combined entropy remains unchanged.
Problem 30:
Tightening a guitar string
(A) lowers the string's frequency or pitch by softening the string's restoring force.
(B) raises the string's frequency or pitch by softening the string's restoring force.
(C) raises the string's frequency or pitch by stiffening the string's restoring force.
(D) lowers the string's frequency or pitch by stiffening the string's restoring force.
Problem 31:
Two children are balanced on a seesaw, but one child weighs twice as much as the other child. The heavier child is sitting half as far from the pivot as is the lighter child. Since the seesaw is balanced, the heavier child is exerting on the seesaw
(A) a torque that is equal in amount but oppositely directed to the torque the lighter child is exerting.
(B) a torque that is less than the torque the lighter child is exerting.
(C) a force that is less than the force the lighter child is exerting.
(D) a force that is equal in amount but oppositely directed to the force the lighter child is exerting.
Problem 32:
If you blow carefully across the top of a drinking straw, it will emit a tone. If you now close off the bottom of the straw with your finger, the tone that it emits will
(A) go down by an octave (its frequency will decrease by a factor of 2).
(B) stay the same.
(C) go up by an octave (its frequency will increase by a factor of 2).
(D) go down by a fifth (its frequency will decrease by a factor of 1.5).
Problem 33:
The three nonflammable objects in your hand are identical except that one is black, one is white, and one is shiny. You place them in a roaring fire and soon they have the same temperature: 1800 °C. They remain solid. Which one is glowing most brightly?
(A) They are all glowing with equal brightness.
(B) The object that originally appeared white.
(C) The object that originally appeared silver.
(D) The object that original appeared black.
Problem 34:
Your table at a family-style restaurant has a "lazy Susan" in the middle. This large circular platform rotates frictionlessly so that you can "pass" an entree to your friends by placing it on the platform and then rotating the platform. When the server places a new entree on the platform, it
(A) makes it harder to change the platform's angular velocity.
(B) decreases the platform's angular velocity.
(C) increases the platform's angular velocity.
(D) makes it easier to change the platform's angular velocity.
Problem 35:
You're at the lake and watch two children jump off a dock. They jump at the same time and at the same speed, but the boy jumps mostly upward while the girl jumps mostly forward. After they leave the dock,
(A) the two children reach the water at the same moment and at the same distance from the dock.
(B) the two children reach the water at the same moment and but the girl travels farther from the dock than does the boy.
(C) the boy reaches the water before the girl.
(D) the girl reaches the water before the boy.
Problem 36:
The second kind of perpetual motion machine provides an inexhaustible supply of mechanical work (or the equivalent of work), but consumes only heat from its constant-temperature environment. An example would be a black box that absorbs heat from the 70 °F room air and converts that heat into electricity forever. This form of perpetual motion machine is impossible because it
(A) violates the law of thermal equilibrium.
(B) violates the law of entropy.
(C) violates the law of conservation of energy.
(D) violates the law of conservation of momentum.
Problem 37:
You are practicing tennis alone by hitting a tennis ball forward toward a cement wall. Each time the ball hits the wall, it bounces backward at high speed so that you can hit it again. During its bounce, the ball
(A) retains approximately all of its energy but transfers more forward momentum than it had to the wall.
(B) retains approximately all of its energy but transfers most of its momentum to the wall.
(C) retains approximately all of its energy and momentum.
(D) retains approximately all of its momentum but transfers most of its energy to the wall.
Problem 38:
You are carrying a child on your back as you walk down a hill. The child is traveling straight at a steady speed. In which direction is the force you are exerting on the child?
(A) Downhill (in the direction of your velocity).
(B) Upward (vertical).
(C) Forward (horizontal).
(D) Upward and forward (between vertical and horizontal).
Problem 39:
You are standing in a slow-moving stream, facing upstream so that the water is coming toward the front of your body. You are wearing shorts and the water level is slightly above your bare knees. The water experiences perfect laminar flow around each of your nearly cylindrical legs. You measure the water pressure at a specific altitude below your right knee and find that the water pressure is
(A) largest on the front of your leg, medium on the sides of your leg, and smallest on the back of your leg.
(B) the same all the way around your leg, since you are measuring the pressure at constant altitude.
(C) smallest on the front of your leg, largest on the sides of your leg, and medium on the back of your leg.
(D) largest on the front and back of your leg and smallest on the sides of your leg.
Problem 40:
Running on soft dry sand is exhausting, so you switch to running on hard wet sand. The hard wet sand removes less energy from you because
(A) it pushes up on your foot just as hard as your foot pushes on it, unlike the soft dry sand.
(B) it stops the downward motion of your foot faster and thus absorbs more of your momentum.
(C) it barely moves downward as you push downward on it, so you do almost zero work on it.
(D) it stops the downward motion of your foot faster and thus absorbs less of your momentum.
Problem 41:
If you strike a stiff, spring-like surface with a mallet and listen to the sound it emits, you'll notice that this sound is more complicated than that emitted by a string or a thin bar. That's because surfaces
(A) have overtones that are not integer multiples of their fundamental frequencies.
(B) are harmonic oscillators.
(C) have overtones that are integer multiples of their fundamental frequencies.
(D) are not harmonic oscillators.
Problem 42:
A hot air balloon is passing over your head when the pilot turns on the flame and heats up the air inside the balloon's envelope (the balloon's fabric skin). That envelope is open at the bottom, where the flame heats it. As the temperature of the air inside the unsealed envelope increases, the
(A) air molecules flow into the envelope's opening and the density of the air inside the envelope increases.
(B) upward buoyant force on the balloon increases and it begins to rise.
(C) air molecules flow into the envelope's opening and the pressure of the air inside the envelope increases.
(D) air molecules flow out of the envelope's opening and the weight of the air inside the envelope decreases.
Problem 43:
A dog and a cat jump horizontally off a wall at the same moment and soon land on the level horizontal field that extends outward from the base of the wall. The dog weighs twice as much as the cat, but the cat was moving forward horizontally twice as fast as the dog when the two animals left the wall. In this situation,
(A) the dog lands first, but both animals land at approximately the same distance from the wall.
(B) both animals land at approximately the same time and at approximately the same distance from the wall.
(C) both animals land at approximately the same time, but the cat lands considerably farther from the wall than the dog does.
(D) the dog lands first, but the cat lands considerably farther from the wall than the dog does.
Problem 44:
When water rushing through a fire hose flows around a bend in that hose, its pressure changes. The water pressure
(A) decreases near the inside of the bend and increases near the outside of the bend.
(B) increases near the inside of the bend and increases near the outside of the bend.
(C) decreases near the inside of the bend and decreases near the outside of the bend.
(D) increases near the inside of the bend and decreases near the outside of the bend.
Problem 45:
In the game of shuffleboard, you push plastic disks forward and then release them so that they slide across a level playing surface. Once you release a disk, you are no longer pushing and it gradually skids to a stop. Its final position determines your score. As each disk skids to a stop, what becomes of the kinetic energy it had when you released it? That energy is
(A) now gravitational potential energy in the disk.
(B) still present in the disk, as it must be because kinetic energy is conserved and can't be created or destroyed.
(C) now thermal energy in the disk and playing surface.
(D) now elastic potential energy in the disk.
Problem 46:
You add a teaspoon of salt to a glass of pure water. The salt initially sits at the bottom of the water, but it slowly dissolves so that eventually you have a glass of salt water. Which has more entropy: the glass of pure water with salt sitting at its bottom or the glass of salt water?
(A) They have the same entropy because water's entropy is independent of its purity.
(B) They have the same entropy because entropy is conserved.
(C) The glass of salt water has more entropy.
(D) The glass of pure water with salt at its bottom has more entropy.
Problem 47:
You are pulling a wagon full of children up a hill at constant velocity. Which one of the following statements is true?
(A) The net force on the wagon is zero and you are doing work on the wagon.
(B) The net force on the wagon is zero and you are doing zero work on the wagon.
(C) The net force on the wagon is uphill and you are doing zero work on the wagon.
(D) The net force on the wagon is uphill and you are doing work on the wagon.
Problem 48:
A cross-country skier is struggling to get up a hill, so you offer to help. As the skier passes you, you reach out with your hand and exert an uphill force of 80 N (18 pounds) on the skier. When you do this, the skier exerts
(A) a downhill force of 80 N on you.
(B) a downhill force of somewhat more than 80 N on you.
(C) a downhill force of somewhat less than 80 N on you.
(D) no downhill force on you at all.
Problem 49:
A gust of wind shakes your home and causes a hanging chandelier to begin swinging gently back and forth on its support chain. When its overall motion is small, the time it takes the chandelier to complete one full oscillation of that motion (its period of oscillation) does not depend on
(A) the chandelier's weight, but it does depend on the chandelier's amplitude of motion.
(B) either the chandelier's weight or the chandelier's amplitude of motion.
(C) the length of the chain supporting the chandelier.
(D) the chandelier's amplitude of motion, but it does depend on the chandelier's weight.
Problem 50:
A skateboarder rides swiftly up the edge of a bowl-shaped surface and leaps into the air. While in the air, the skateboarder flips upside and tosses the skateboard from hand to hand. The skateboarder then rides safely back down the bowl. During the time that the skateboarder and skateboard are not touching anything, one aspect of their motion that is constant is their total (or combined) [note: neglect any effects due to the air]
(A) momentum.
(B) angular momentum.
(C) velocity.
(D) angular velocity.
Problem 51:
How is a steam engine able to obtain work (ordered energy) from hot steam?
(A) The hot steam has a large amount of entropy and that entropy can be converted into work.
(B) As heat flows from the hot steam to the colder environment, the steam engine is able to divert a fraction of that heat and convert it into work.
(C) The hot steam has a large amount of momentum and that momentum can be converted into work.
(D) The steam's thermal energy can be converted into work because both are energy and energy is conserved.
Problem 52:
You and several friends take turns bungee jumping from Beta Bridge, using the same spring-like bungee cord. Near the end of your turn, you bounce gently up and down on the cord with a period (the time it takes for each bounce) of 1 second. One friend has your same height, but is heavier than you. Another friend has your same weight, but is shorter than you. During your friends' turns, what are the periods of their bounces?
(A) Your heavier friend has a period of 1 second; your shorter friend has a period shorter than 1 second.
(B) Your heavier friend has a period longer than 1 second; your shorter friend has a period of 1 second.
(C) Your heavier friend has a period of 1 second; your shorter friend has a period longer than 1 second.
(D) Your heavier friend has a period longer than 1 second; your shorter friend has a period longer than 1 second.
Problem 53:
It is a beautiful summer day and the residents of a high-rise apartment building are eating dinner on their balconies. A resident accidentally knocks an empty glass off a balcony that is about 80 meters (260 feet) above the cement patio. The glass would have smashed on that patio after falling for 4 seconds, however, a quick-witted resident catches the glass after it has fallen for only 2 seconds. How far above the patio was the glass when it was caught?
(A) Approximately 40 meters above the patio.
(B) Approximately 30 meters above the patio.
(C) Approximately 60 meters above the patio.
(D) Approximately 50 meters above the patio.
Problem 54:
You are at the gym, exercising on a step machine. You have one foot on each of the machine's pedals and you move those pedals up and down as you step. The pedals always push upward on your feet, but they push upward harder on your feet while moving downward than they do while moving upward. When during this exercise is your foot transferring energy to the pedal that it is touching?
(A) When that pedal is accelerating.
(B) As that pedal moves downward.
(C) As that pedal moves either upward or down.
(D) As that pedal moves upward.
Problem 55:
You take off your shoes to sneak quietly into your home late at night. Unfortunately, it's too dark to see the concrete block your friend left on the floor and your big toe collides with it. The block doesn't move and your foot comes to a complete stop due to the impact. Luckily, you are wearing soft woolen socks because when your foot stops during the impact, your toe transfers
(A) less energy to the block than it would have if you had not been wearing socks.
(B) less momentum to the block than it would have if you had not been wearing socks.
(C) less velocity to the block than it would have if you had not been wearing socks.
(D) the same momentum, whether or not you are wearing socks, but that transfer takes more time when you are wearing socks.
Problem 56:
Suppose a musician is playing a wind instrument (e.g., a flute, clarinet, or oboe) and the density of the air suddenly decreases. There is no change in the air's pressure or in how the musician is playing the instrument. What happens to the instrument's sound?
(A) The instrument's volume (amplitude) increases.
(B) The instrument's pitch (frequency) decreases.
(C) The instrument's volume (amplitude) decreases.
(D) The instrument's pitch (frequency) increases.
Problem 57:
Two puppies are fighting over a toy. Each puppy grips one end of that toy in its mouth and pulls. Suddenly, the puppy on the right pulls especially hard on the toy and moves its end of the toy to the right. The other puppy manages to keep its end of the toy from moving. Alas, the toy breaks and the game ends. Breaking the toy required energy and that energy was provided
(A) by both puppies, but most was provided by the puppy on the right.
(B) in equal amounts by the two puppies.
(C) only by the puppy on the left.
(D) only by the puppy on the right.
Problem 58:
When wood burns in air, the water and carbon dioxide molecules that form as the result of combustion reactions have
(A) more chemical potential energy than the original wood and air molecules
(B) more chemical momentum than the original wood and air molecules
(C) less chemical potential energy than the original wood and air molecules
(D) less chemical momentum than the original wood and air molecules
Problem 59:
You are swinging a bucket full of water around you in a big horizontal circle at a constant speed. You are at the center of its circular path. The net force on the bucket points directly
(A) toward you.
(B) downward.
(C) away from you.
(D) along the bucket's velocity (along its direction of travel).
Problem 60:
You are trying to set the world's record for drinking water through the tallest drinking straw. What could you do to have the best chance of setting this record?
(A) Use the narrowest drinking straw you can find.
(B) Use the widest drinking straw you can fit in your mouth.
(C) Choose a bad-weather day when the atmospheric pressure is as small as possible.
(D) Choose a good-weather day when the atmospheric pressure is as large as possible.