Physics W.E.M.P. Quiz

Two billiard balls having the same mass and speed roll toward each other. What their combined momentum after they meet? a. 0 b. half the sum of their original momentums c. twice the sum of their original momentums d. impossible to determine without additional information.

a. 0

The power required to exert 1 N force, over the distance of 1 m in 1 sec is a. 1 w b. 2 w c. 1/3 w d. 3 w e. none of these

a. 1 w

Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide and stick. The combined mass moves at a. 1/2 m/s b. 1/3 m/s c. 1/6 m/s d. 3/4 m/s e 1.5 m/s

a. 1/2 m/s

A 4 kg ball has a momentum of 12 kg *m/s. What is the ball's speed? a. 3 m/s b. 4 m/s c. 48 m/s d. none of these

a. 3 m/s

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is a. greater b. smaller c. the same

a. greater

Padded dash boards in cars are safer in an accident than non padded ones because an occupant hitting the dash has a. increased time of impact b. decreased time of impact c. decreased impulse d. increased momentum

a. increased time of impact

When you are in the way of a fast-moving object and can't get out the way, you will suffer a smaller force of impact if you decrease its momentum over a a. long time b. short time c. same way either way

a. long time

An object that has kinetic energy must be a. moving b. falling c. at an elevated d. at rest e. none of these

a. moving

If you push for a half hour or a whole hour against a stationary wall a. no work is done b. half as much work is done during the half hour c. twice as much work is done during the half hour d. it is impossible to determine how much work is done

a. no work is done

The ball rolling down an incline has its maximum potential energy at a. the top b. a quarter of the way down c. halfway down d. the bottom

a. the top

It takes 40 J to push a large box 4 m across a floor. Assuming the push is in the same direction as the move, what is the magnitude of the force of the box? a. 4 N b. 10 N c. 40 N d. 160 N e. none of these

b. 10 N

Do 100 J of work in 50 s and your power output is a. 1/2 w b. 2 w c. 4 w d. 50 w e. 5000 w

b. 2 w

A car that travels twice as fast as another when braking to a stop will skid a. twice as far b. four times as far c. depends on the mass of the cars

b. four times as far

If an object has kinetic energy, then it also must have a. impulse b. momentum c. acceleration d. force e. none of these

b. momentum

If a ping pong ball and a golf ball are both moving in the same direction with the same amount of kinetic energy the speed of the ping pong ball must be a. less than the golf ball b. more than the golf bball c. the same as the golf ball d. impossible to predict without additional information

b. more than the golf ball

Which has greater kinetic energy, a car traveling at 30 km/hr or a car of half the mass traveling at 60 km/hr? a. the 30 km/hr car b. the 60 km/hr car c. both have the same kinetic energy d. more information is needed about the distance traveled

b. the 60 km/hr car

A block of ice sliding down an incline has a max speed at a. the top b. the bottom c. halfway down d. difficult to predict without knowing the slope of the incline e. difficult to predict without knowing the coefficient of friction

b. the bottom

It is correct to say that impulse is equal to a. momentum b. the change in momentum c. the force multiplied by the distance the force acts d. velocity multiplied by time.

b. the change in momentum

The difference between impulse and impact force involves the a. distance the force acts. b. time the force acts. c. difference between acceleration and velocity. d. mass and its effect or resisting a change in momentum,

b. time the force acts.

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of a. less than 1 unit b.more than 1 unit c. 1 unit d. not enough information

c. 1 unit

The change in momentum, in kg * m/s, that occurs when a 1.0 kg ball traveling at 4.0 m/s strikes a wall and bounces back at a. 2 b.4 c. 6 d. 8

c. 6

A 5,000 kg freight car runs into a 10,000 kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. what was the initial speed of the 5,000kg car? a. 4 m/s b. 5 m/s c. 6 m/s d. 8 m/s e. none of these

c. 6 m/s

The conservation of momentum is most closely related to a. Newton's 1 law b. Newton's 2 law c. Newton's 3 law d. Newton's 4 law

c. Newton's 3 law

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of impact about time as great as fro a stiff-legged landing. In this way the average force your body experiences is a. less than 1/10 as great b. more than 1/10 as great c. about 1/10 as great d. about 10 times as great.

c. about 1/10 as great

You're driving down the highway and a bug splatters into your windshield. Which under goes the greater change in momentum during the time of contact? a. the bug b. your car c. both the same

c. both the same

A rifle recoil while firing a bullet. The speed of the rifle's recoil is small because the a. force against the rifle is smaller than against the bullet b. momentum is mainly concentrated in the bullet c. rifle has much more mass than the bullet d. momentum of the rifle is smaller

c. rifle has much more mass than the bullet

No work is done by gravity on a bowling ball that rolls along a bowling alley because a. no force acts on the ball b. no distance is covered by the ball c. the force on the ball is at a right angle to the ball's motion d. no potential energy is being converted to kinetic energy e. its kinetic energy remains constant

c. the force on the ball is at a right angle to the ball's motion.

If you do work on an object in one-third the usual time, your power output is a. one third the usual power output b. the usual power output c. three time the usual power output d. impossible to predict without additional information

c. three times the usual power output

A 2 kg mass is held 4 m above the ground. What is the approximate potential energy of the mass with respect to the ground? a. 6 J b. 8 J c. 32 J d. 80 J e. none of these

d. 80 J

An object may have potential energy because of its a. speed b. acceleration c. momentum d. location e. none of these

d. location

In order to catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion.. Doing this reduces the force of impact on the player's hand principally because the a. force of impact is decreased b. relative velocity is less c. time of impact is increased d. time of impact is decreased e. none of these.

d. time of impact is increased

A moving object has a. speed b. velocity c. momentum d. energy e. all of these

e. all of these

An object at rest may also have a. speed b. velocity c. momentum d. kinetic energy e. potential energy

e. potential energy