You are pushing a shopping cart full of food to the top of a mountain for a party. There are two roads to the top, one twice as long as the other. Each road has a steady slope, although the shorter road is considerably steeper than the longer road. If you take the longer road to the top, [neglect friction or effects due to the air]

You are pulling a wagon full of children up a hill at constant velocity. Which one of the following statements is true?

You are enjoying life at a lake when a canoe full of kids rapidly approaches the dock on which you are sitting. You push the canoe backward gently and safely reduce its velocity to zero just before it crashes into the dock. If you had let the canoe crash into the dock, so that the dock suddenly reduced the canoe's velocity to zero, the canoe would have

The door in front of you is completely free to rotate on its hinges. Only you can affect the door's rotation. You push the door several times in different places and the door's

When a person falls onto the ground, that person does not bounce. When the person instead falls onto a trampoline, the person bounces upward. Why does the trampoline allow the person to bounce?

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]

You take off your shoes to sneak quietly into your room late at night. Unfortunately, it's too dark to see the new 84" flat-screen TV your friend left on the floor and your big toe collides with it. The TV 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

As each acorn falls from an oak branch located 20 meters above the ground, that acorn takes about 2 seconds to hit the ground. A squirrel on a branch 10 meters above the ground decides to snatch one of those falling acorns as it passes by the squirrel's branch. How long after the acorn starts to fall does the squirrel snatch the passing acorn?

As you accelerate forward at the start of a marathon (a long-distance running race), what force or forces is the level ground exerting on you?

Which one of the following people is experiencing zero net force?

When the batter in a baseball game hits the baseball with the middle part of the baseball bat, the bat vibrates loudly and may even shatter. Why does the ball bounce relatively weakly off the bat in this situation?

You are walking a dog on a leash when the dog begins chasing a rabbit. As you and the dog move rapidly forward in a straight line at a steady speed, compare the horizontal forces you and the dog exert on the leash that connects you. [Neglect the leash's mass and weight]

Your friend throws a lively (bouncy) ball toward you from the other side of a field. To catch that ball, you must let your hands move in the direction of the ball's velocity. If you instead hold your hands motionless as you try to grab the ball, the ball will bounce off your hands and you will drop it. Why does letting your hands move with the ball's motion improve your ability to catch the ball?

You are exercising at the gym and there is a heavy weight resting motionless on the floor in front of you. You lift that weight upward until it is above your head and you then lower it gently downward to its original, motionless position on the floor. Compare the work you did on the weight while raising it to the work you did while lower it.

A car heading northward on a road skids to a stop to avoid hitting something in the road. As the car skids to a stop, what work is done? [Neglect effects due to the air and any movement of the road itself]

You are acting in a movie and the script calls for you to weigh yourself on a spring scale. Being a vain actor, you want the scale to read less than your weight, so you film the scene in an elevator. For the scale to read less than your weight as you weigh yourself in that elevator, the elevator must be

It is difficult to cut thick cardboard with a pair of scissors. The farther the cardboard is from the scissors' pivot, the harder it becomes for you to rotate the scissors closed because the cardboard then

You are stretching a rubber band by holding its left end motionless with your left hand while you move its right end to the right with your right hand. The rubber band's energy increases as it stretches, so where is that energy coming from?

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 girl jumps mostly upward while the boy jumps mostly forward. After they leave the dock,

You are a firefighter and the alarm sounds in your fire station. As you slide down the fire pole at constant velocity, your gravitational potential energy is decreasing. What is becoming of that energy?

You are pushing a table across the floor. As the table moves forward at constant velocity, compare the horizontal force you exert on the table to the horizontal frictional force the floor exerts on the table. [Neglect any effects due to the air]

It has been a long day and you casually throw your backpack onto your bed. The backpack is in free fall prior to touching the bed and is moving downward. When during its initial landing on the bed does the backpack reach its maximum downward speed?

A dozen children are riding the painted wooden horses on a carousel at the fair. They all sit on horses at the outer edge of the carousel disk, where they can see and be seen. If those children had instead sat on horses near the center of the carousel disk, how would that have changed the carousel's behavior?

You are playing soccer on an ordinary level soccer field. You kick the ball and it travels high above the ground before landing in the goal. Nothing touches the ball as it arcs from your foot to the goal, so when during that arc does the ball have the slowest speed (the smallest amount of velocity)? [Neglect any effects due to the air]

A plastic step used in an exercise class consists of a plastic board supported at each end by a plastic block. When you step on the board and stand motionless, the board bends downward 1 millimeter. Your friend weighs twice as much as you do. When your friend steps on the board and stands motionless, the board bends downward

You place a stiff ruler on a pencil and then stack coins on the two ends of the ruler until it is balanced. The ruler and its coins are then able to remain motionless on the pencil pivot. What did you have to do to achieve this balanced condition?

You toss a basketball straight up. Disregarding any effects of due to the air, what force or forces are acting on the basketball while it is above your hands?

If you drop a baseball and a bowling ball from rest at the same time and from the same height, how will they move? [Neglect any effects due to the air]

Your new yacht (new boat) is being launched and is moving down a ramp at constant velocity, on its way to the water. You are standing on the yacht, waving at your admiring friends. In which direction is the yacht pushing on you?

You are riding your motorcycle off a building's horizontal roof and expect to land on the level parking lot below. Unfortunately, you fall asleep just as the motorcycle leaves the roof and immediately let go of the motorcycle. The motorcycle is much heavier than you. When and where do the two of you land on the ground? [Neglect any effects due to the air]