Physic

Q: The 1 cubic meter of fresh water at the top of a 100 m hydroelectric dam has a potential energy of 980,000 N. At the bottom of the dam,a. The kinetic energy is 980,000 Nb. All of the kinetic energy can be converted to electricityc. Some of the kinetic energy is converted to electricity and some is lost.d. The residual potential energy of the water is 9,800 N

Q: After the dropped box hits the floor, its kinetic energy isa. 0b. equal to its potential energyc. is converted to internal energyd. none of the above

Q: A barbell is easier to twist when its weights area. close to the axis of rotationb. near the ends of the barc. heavyd. lighte. none of the above

Q: The total kinetic plus potential energy of a body a. can be negative b. always stays constant if the body is freely falling c. always stays constant if friction is acting d. can remain constant even if the body's speed is decreasing

Q: Linear momentum is conserved ina. an inelastic collisionb. an elastic collisionc. any collision where two objects rebound off each otherd. none of the above

Q: A mechanic working on a 100 m radar tower drops a hammer weighing 44.5 N. The work done on the hammer as it falls is:a. 4.45 N-m b. 44.5 N-m c. 445 N-md. 4,450 N-m

Q: The mass of 1 cubic meter of fresh water at the top of a 100 m hydroelectric dam is 1,000 kg and it has a potential energy of 980,000 N. At the bottom of the dam, the speed of the moving water is:a. 9,800 m/s b. 1,960 m/s c. 44.3 m/sd. 98 m/s

Q: The mass of 1 cubic meter of fresh water is 1,000 kg. At the top of a 100 m hydroelectric dam the potential energy of the cubic meter of water is:a. 10,000 N b. 98,000 N c. 100,000 Nd. 980,000 N

Q: The mass of 1 m3 of fresh water is 1,000 kg. At the top of a hydroelectric dam the potential energy of the water is:a. 1,000 Nb. 9,800 Nc. 500 Nd. There is not enough information to calculate the potential energy

Q: Suppose after reaching the bottom he then continues sliding up another icy slope on the other side of the valley. When he finally comes to a stop he will have reached a heighta. equal to the height he started from on the other hillb. less than the height he started from on the other hillc. more than the height he started from on the other hilld. none of the above

Q: He slides all the way down to the valley bottom where his gravitational potential energy becomes zero. His kinetic energy at the bottom will bea. 0 J b. 500 J c. some value between 0 and 500 Jd. none of the above

Q: He slides part way down the hill to a point where his gravitational potential energy is 200 J. His kinetic energy at that point will bea. 200 Jb. 300 Jc. some unknown value between 0 and 500 Jd. none of the above

Q: His kinetic energy at the top of the hill isa. 0 J b. 500 Jc. some value between 0 and 500 Jd. none of the above

Q: An object moving in a circle at a steady speed has a. constant linear momentum b. constant angular momentum c. constant velocity d. constant acceleration

Q: A watt is equal to a. 746 horsepower b. one calorie c. one joule d. 1 J/s e. a unit of energy

Q: About how many 100W light bulbs would you have to light up to use energy at the rate of one horsepower?a. one or twob. seven or eightc. the question doesn"t make sensehp and W are unrelatedd. dozense. none of the above

Q: After an elastic collision of two balls, the kinetic energies of the two balls are measured to be 12J and 24J. What can be said about the kinetic energy of the two balls before the collision?a. nothingnot enough information is givenb. the balls had the same energies, 12J and 24J respectivelyc. the total kinetic energy of the two balls was 36Jd. none of the above

Q: A person runs up a long flight of stairs in 10 seconds. If the person's weight is 600 N and the vertical height of the stairs is 20 meters, the person's power output is a. 0 b. 3 W c. 30 W d. 1,200 W e. 12,000 W

Q: A 2 kg car moving towards the right at 4 m/s collides head on with an 8 kg car moving towards the left at 2 m/s, and they stick together. After the collision, the velocity of the combined bodies is a. 0 b. 0.8 m/s towards the right c. 0.8 m/s towards the left d. 2.4 m/s towards the right e. 2.4 m/s towards the left

Q: Which of the following quantities are conserved in an isolated system?a. mass b. energy c. momentumd. all of the above

Q: Using a lever to move a rock reduces the force a person must exert. What does it do to the work the person must do?a. it reduces the work also b. the work stays the same c. the work increasesd. none of the above

Q: When we say work is done against a force, we mean the force doesa. none of the work b. positive work c. negative workd. zero work

Q: When we say work is done by a force, we mean the force doesa. all the work b. positive work c. negative workd. zero work

Q: What is the magnitude of the change in the object's momentum?a. 150 kg m/sb. 50 kg m/sc. 75 kg m/sd. undeterminednot enough information givene. none of the above

Q: What is the work done by the force?a. 150 Jb. 50 Jc. 75 Jd. undeterminednot enough information givene. none of the above

Q: What is the impulse provided by the force?a. 150 Nsb. 50 Nsc. 75 Nsd. undeterminednot enough information givene. none of the above

Q: You drop the box. As it falls to its original level, its kinetic energy isa. 0 b. 4 J c. 100 Jd. none of the above

Q: The increase of potential energy of the box isa. 0 b. 4 J c. 100 Jd. none of the above

Q: The work you do isa. 0 b. 4 J c. 100 Jd. none of the above

Q: You carry a 20 N box 5 m horizontally across a room. The work you do is a. 0 c. 100 J b. 4 J d. none of the above

Q: The quantity mv is a. the kinetic energy of the crate b. the potential energy of the crate c. the linear momentum of the crate d. the work you do on the crate e. the power you supply to the crate

Q: The quantity Fd/t is a. the kinetic energy of the crate b. the potential energy of the crate c. the linear momentum of the crate d. the work you do on the crate e. the power you supply to the crate

Q: The quantity 1/2 mv2 is a. the kinetic energy of the crate b. the potential energy of the crate c. the linear momentum of the crate d. the work you do on the crate e. the power you supply to the crate

Q: The quantity Fd is a. the kinetic energy of the crate b. the potential energy of the crate c. the linear momentum of the crate d. the work you do on the crate e. the power you supply to the crate

Q: Kinetic energya. is definitely conservedb. is definitely not conservedc. may or may not be conservedd. none of the above

Q: Linear momentuma. is definitely conservedb. is definitely not conservedc. may or may not be conservedd. none of the above

Q: Angular momentuma. is definitely conservedb. is definitely not conservedc. may or may not be conservedd. none of the above

Q: For a body oscillating at the end of a spring, the energy isa. kinetic energyb. elastic potential energyc. gravitational potential energyd. all of the abovee. none of the above

Q: The energy of a ball rolling up an inclined planea. is entirely kineticb. is entirely potentialc. is both kinetic and potentiald. none of the above

Q: Which of the following is not an example of potential energy? a. The energy stored in a pile driver. b. The energy stored in a stretched spring. c. The energy of a body moving across a horizontal surface. d. The energy in the water at the top of a waterfall.

Q: Internal energya. remains constantb. decreasesc. increasesd. varies but in a way that cannot be predicted

Q: Linear momentuma. is definitely conservedb. is definitely not conservedc. may or may not be conserved, depending on the nature of the collisiond. none of the above

Q: Kinetic energya. is definitely conservedb. is definitely not conservedc. may or may not be conserved, depending on the nature of the collisiond. none of the above

Q: Linear momentuma. is definitely conservedb. is definitely not conservedc. may or may not be conserved, depending on the nature of the collisiond. none of the above

Q: Kinetic energya. is definitely conservedb. is definitely not conservedc. may or may not be conserved, depending on the nature of the collisiond. none of the above

Q: If a force on an object is aimed perpendicular to the direction of the object's velocity, the force doesa. no work b. positive work c. negative workd. any of the above

Q: If a force on an object is aimed in the direction of the object's velocity, the force doesa. no work b. positive work c. negative workd. any of the above

Q: If a force on an object is aimed opposite the direction of the object's velocity, the force doesa. no work b. positive work c. negative workd. any of the above

Q: Work is done on an object whena. it moves in a circle at constant speedb. it is accelerated in a straight linec. it is carried horizontally at constant speedd. all of the above

Q: What are the SI units of momentum?a. kg m/s b. pascals c. joulesd. watts

Q: The linear momentum of a truck will be greater than that of a bus ifa. the truck's mass is larger than the bus's but its speed is the sameb. the truck's speed is larger than the bus's but its mass is the samec. the truck's mass and speed are both larger than the bus'sd. any of the above

Q: Kinetic energy is conserved ina. an inelastic collisionb. an elastic collisionc. any collision where two objects rebound off each otherd. none of the above

Q: What does it mean for a physical quantity in a system to be conserved?a. It is used in the most efficient manner possible.b. It stays in its original state forever.c. The total amount of it in the system stays constant.d. none of the above.

Q: A barrel rolling down an inclined ramp has only kinetic energy.

Q: In a closed system, the kinetic energy plus the potential energy is a constant.

Q: If the velocity of an aircraft is doubled, the kinetic energy of the aircraft is also doubled.

Q: The collision between two cars in an accident is an inelastic collision.

Q: When a car comes to a stop its kinetic energy is converted to internal energy in its brakes, heating them up.

Q: A spacecraft can gain energy by passing near a planet.

Q: When more people ride upward in an elevator, more power is required.

Q: A rocket can never go faster than the speed of its exhaust.

Q: A person runs up a long flight of stairs in 10 seconds. If the person's weight is 600 N and the vertical height of the stairs is 20 meters, the person's power output is 1,200 W.

Q: When the box hits the floor its kinetic energy is converted into internal energy.

Q: You drop the box. As it falls to its original level, its kinetic energy is 100 J.

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