Quiz 8

The book takes the same amount of time to go up as it does to come down.

A book is given a brief push to make it slide up a smooth incline (friction is negligible). It comes to a stop and slides back down to the starting point. Which of the following is true? The book takes longer to go up than to come down. There is no way to determine how the going-up and coming-down times compare. The book takes longer to come down than to go up. The book takes the same amount of time to go up as it does to come down.

twice as long as that for the stronger force.

A constant force is exerted on a cart that is initially at rest on an air track. Friction between the cart and the track is negligible. The force acts for a short time interval and gives the cart a certain final speed. To reach the same final speed with a force that is only half as big, the force must be exerted on the cart for a time interval equal to that for the stronger force. half as long as that for the stronger force. four times as long as that for the stronger force. a quarter of that for the stronger force. twice as long as that for the stronger force.

The force the car exerts on the dump-truck is equal in magnitude but opposite in direction to the force exerted by the dump-truck on the car.

A dump-truck collides head-on with a small car. The dump-truck has a mass 10 times larger than the car. The force the car exerts on the dump-truck is equal in magnitude and direction to the force exerted by the dump-truck on the car. The force the car exerts on the dump-truck is equal in magnitude but opposite in direction to the force exerted by the dump-truck on the car. The force the car exerts on the dump-truck is 10 times smaller in magnitude and opposite in direction to the force exerted by the dump-truck on the car. The force the car exerts on the dump-truck is 10 times smaller in magnitude and in the same direction as the force exerted by the dump-truck on the car.

The engine's force on the cars is as strong as the force of the cars on the engine, but the frictional force on the engine is forward and large, while the backward frictional force on the cars is small.

A train engine pulls a series of train-cars. Which of the following correctly describe the situation? Because action always equals reaction, the engine cannot pull the cars - the cars pull backwards just as hard as the engine pulls forward. The engine's force on the cars is as strong as the force of the cars on the engine, but the frictional force on the engine is forward and large, while the backward frictional force on the cars is small. The engine can pull the cars forward only if it weighs more than the cars. The train moves forward because the engine pulls forward slightly harder on the cars than the cars pull backward on the engine. The engine gets the cars to move by giving them a tug during which the force on the cars is momentarily greater than the force exerted by the cars on the engine.

False

According to Newton's third law, rockets should not move. True False

False

Consider a car at rest. We can conclude that the downward gravitational pull of the Earth on the car and the upward normal force of the Earth on it are equal and opposite because the two forces form an interaction pair. True False

The acceleration of the player is much larger than the Earth.

Imagine a basketball player jumping off the surface of the Earth for a rebound. Which of the following statements is true? The acceleration of the player must be smaller than the acceleration of the Earth. The acceleration of the player is much larger than the Earth. The acceleration of the player must be equal in magnitude to the acceleration of the Earth, but in the opposite direction. The acceleration of the player must be equal to the acceleration of the Earth.

the acceleration of the system of blocks depends on the total mass of the blocks.

Two blocks are connected by a thin string. If a force is applied to one of the blocks so that the second one is pulled along the acceleration of the system of blocks only depends on the mass of the block that has the force applied to it. the acceleration of the system of blocks depends on the total mass of the blocks. the acceleration of the system of blocks only depends on the mass of the block that does not have the force applied to it. the acceleration of the system of blocks is independent of the mass of the blocks.