Physics Final

An object starts at rest from a height of 50 meters. Its total amount of mechanical energy is 500 Joules. The object begins a free-falling motion; there is no air resistance. When it has fallen to a height of 20 meters, its potential energy will be ____ Joules and its total amount of mechanical energy will be ____ Joules. Select the two numbers that fill in the blanks in their respective order. a. 200, 300 b. 200, 500 c. 300, 200 d. 300, 500 e. 500, 200

200, 500

An object is moving uphill at a constant speed. Which one of the following statements is true of the object? a. Its kinetic energy is constant. b. Its kinetic energy is increasing. c. Its kinetic energy is decreasing.

Its kinetic energy is constant.

A roller coaster car is moving upward towards the top of a loop and slowing down. Which one of the following statements is true of the roller coaster car? a. Its kinetic energy is constant. b. Its kinetic energy is increasing. c. Its kinetic energy is decreasing.

Its kinetic energy is decreasing.

Which one of the following objects has the greatest amount of momentum? a. A turtle that slowly makes its way across the road. b. The car that is parked along the side of the road. c. The stop sign that warns cars to stop when they reach the end of the road.

a. A turtle that slowly makes its way across the road.

An object is moving horizontally and speeding up. Which one of the following statements is true of the object? a. Its potential energy is constant. b. Its potential energy is increasing. c. Its potential energy is decreasing.

. Its potential energy is constant.

Consider the description given to Object A and Object B below: Object A: a 3-kg object moving at 4 m/s. Object B: a 2-kg object moving at 5 m/s. Which one of the following statements describing the two objects is true? a. Object A has more momentum than Object B. b. Object B has more momentum than Object A. c. Object A and Object B have the same amount of momentum.

. Object A has more momentum than Object B.

Which is the best definition of the term potential energy? a. Potential energy is the energy due to motion. b. Potential energy is the work that an object does. c. Potential energy is the energy due to temperature. d. Potential energy is the energy stored in an object due to vertical position (height)

. Potential energy is the energy stored in an object due to vertical position (heigh

The amount of momentum an object possesses depends upon two quantities. What are the two quantities? Select two answers. a. The mass of the object. b. The speed of the object. c. The weight of the object. d. The acceleration of the object. e. The direction that the object is moving.

. The mass of the object. b. The speed of the object.

The total mechanical energy possessed by an object is equal to ____. a. its kinetic energy b. its potential energy c. its kinetic energy plus potential energy d. its kinetic energy minus potential energy e. its potential energy minus kinetic energy

. its kinetic energy plus potential energy

A leftward force acts upon an object that is moving to the right. Such a force does _____. a. positive work b. negative work c. no work at all

. negative work

Two Silly Putty balls of equal mass are moving in opposite directions at equal speeds. The balls collide head on and immediately stop. Which one of the following statements is true about the collision? a. Both objects conserve their own individual momentum. b. Momentum is not conserved by the system of two Silly Putty balls. c. The system starts with some total momentum and ends with no total momentum. d. ... nonsense! None of these statements are true.

... nonsense! None of these statements are true.

A 140-kg red bumper car moving east at 2.25 m/s collides with a 110-kg blue car that is at rest. The bumpers of the two cars entangle and they move together after the collision. Assuming that the system is isolated, determine the final velocity of the cars. Use the notation that east is the positive direction and west is the negative direction.

1.26m/s

A sledder has 600 J of potential energy and 200 J of kinetic energy at one point on a steep hill. How much kinetic energy will the sledder have at the bottom of the hill? (Assume negligible air resistance and friction.) a. 0 J b. 200 J c. 400 J d 600 J e. 800 J

800 J

An object is moving up a short incline and speeding up. Which one of the following statements is true of the object? a. Its potential energy is constant. b. Its potential energy is increasing. c. Its potential energy is decreasing.

Its potential energy is increasing.

Which is the best definition of the term kinetic energy? a. Kinetic energy is the energy due to motion. b. Kinetic energy is the work that an object does. c. Kinetic energy is the energy due to temperature. d. Kinetic energy is the energy stored in an object due to vertical position (height).

Kinetic energy is the energy due to motion.

What quantity causes a momentum change and is equal to the amount of momentum change? a. The acceleration of gravity. b. The acceleration of the object. c. The net force that acts upon the object. d. The impulse encountered by the object.

The impulse encountered by the object.

Which of the following changes would cause the kinetic energy of an object to increase? a. The speed of the object changes. b. The mass of the object increases. c. The height of the object decreases. d. The object does work on another object.

The mass of the object increases.

Which one of the statements is ALWAYS true of an object that conserves its mechanical energy? a. Neither its kinetic nor its potential energy undergo a change. b. The sum of its kinetic and potential energy remains constant. c. Its kinetic energy remains a constant value; its potential energy may or may not change. d. Its potential energy remains a constant value; its kinetic energy may or may not change.

The sum of its kinetic and potential energy remains constant.

Consider the following statement. Work is a _______ acting upon an object for a given ______. The amount of work done is equal to the change in ________ of the object. Which three words accurately complete the sentence in the order listed? a. force, mass, velocity b. force, distance, energy c. force distance, velocity d. impulse, time, momentum e. impulse, mass, momentum

b. force distance, energy

If an object has energy, then one can be certain that it..... a. is moving b. it is at a high temperature c. is raised above the ground d. has the ability to do work on another object

has the ability to do work on another object

Consider the description given to Object A and Object B below: Object A: a 6-kg object moving at 1 m/s. Object B: a 2-kg object moving at 6 m/s. Based on this description, Object A has _____ momentum compared to Object B. a. the same amount of b. twice as much c. four times as much d. one-half as much e. one-fourth as much

one-half as much

Momentum is _____. a. the speed that an object has b. the rate at which an object changes its motion c. the product of the mass and velocity of an object d. the product of the mass and acceleration of an object

the product of the mass and velocity of an object

Machine A and Machine B are doing the same task. Machine A does it in 10 seconds and Machine B does in in 20 seconds. This is evidence that Machine A does ____ work as Machine B and has _____ the power of Machine B a. the same, twice b. the same, one-half c. twice as much, one-half d. twice as much, twice the e. one-half as much, the same

the same, twice