31. Which of the following is true when considering a nuclear process?
a. Fission always releases more energy than nuclear fusion.
b. The law of conservation of energy does not apply to nuclear processes.
c. Both fission and fusion are examples of mass being converted to energy.
d. Nuclear fission converts mass to energy when small nuclei come together to create new heavier particles.
32. The mechanical energy of a skidding automobile is 100,000 joules (J). When it finally comes to rest at the bottom of a hill it has a potential energy of 10,000 J. Approximately how much energy was converted to heat?
a. 10 J
b. 90,000 J
c. 110,000 J
d. This cannot be determined without knowing the mass of the automobile.
33. Calculations to determine the amount of Calories used in various activities take into account the mass of the person doing the activity. This is important because
a. work involves moving a force through a distance. Moving more mass involves doing more work, so more energy would be used during the movement of a larger person.
b. since kinetic energy depends only on mass, the mass of a person affects Calorie usage.
c. it is easier for a larger person to convert potential energy to kinetic energy.
d. a larger person takes in more Calories per day than a smaller person.
34. Work is something we all do, but which of the following is the most accurate scientific description of work?
a. Work is the result of using a force to move something a specific distance.
b. Work can be measured in newtons.
c. Work can be calculated from the total distance an object is moved regardless of applied force.
d. Work can be related to power by multiplying the work times the seconds that the work was carried out.
35. In which of the following cases is the most power generated?
a. lifting a 10 kg box 1.5 meters
b. lifting a 15 kg box 0.50 meters
c. Both require the same amount of power.
d. This comparison cannot be made without more information.
36. To qualify as a machine, which of the following must be true about using an object to do work?
a. Force out must be less than force in.
b. Force in must be less than force out.
c. Work in must be less than work out.
d. Force in must equal force out.
37. How much distance would you expect to move an object if the machine you were using (such as crowbar or a lever) involved a movement of .010 m from an input of 200 N, but the output force was 500 N? (Ignore any slight thermal energy involved.)
a. Assuming the machine to be ideal, the output distance would be 0.10 m.
b. 0.0040 m
c. 1000 m
d. 0.25 m
38. A machine is going to be used to lift a 1000 N object. Which of the following would be true if the machine is very efficient?
a. Operating the machine would cause a small amount of heat to be lost as thermal energy.
b. The output work would be small compared to the input work.
c. The mechanical advantage would be large.
d. Friction would be very high.
39. A rod, a pivoting rod such as a baseball bat, and a wheelbarrow are all examples of levers. Which of the following is true of a second-class lever?
a. The input force is applied between the output force and the fulcrum.
b. The output force is in the opposite direction from the input force.
c. The output force is exerted between the input force and the fulcrum.
d. The output force is always equal to the input force.
40. Our skeletal and muscle systems make use of some simple machine principles. For example, holding your head up requires force. Which of the following is an accurate comparison of levers and anatomy?
a. Your head and neck act as a first-class lever.
b. Your head and neck act as a second-class lever.
c. Your head and neck act as a third-class lever.
d. Your head and neck act as a fourth-class lever
a. Fission always releases more energy than nuclear fusion.
b. The law of conservation of energy does not apply to nuclear processes.
c. Both fission and fusion are examples of mass being converted to energy.
d. Nuclear fission converts mass to energy when small nuclei come together to create new heavier particles.
32. The mechanical energy of a skidding automobile is 100,000 joules (J). When it finally comes to rest at the bottom of a hill it has a potential energy of 10,000 J. Approximately how much energy was converted to heat?
a. 10 J
b. 90,000 J
c. 110,000 J
d. This cannot be determined without knowing the mass of the automobile.
33. Calculations to determine the amount of Calories used in various activities take into account the mass of the person doing the activity. This is important because
a. work involves moving a force through a distance. Moving more mass involves doing more work, so more energy would be used during the movement of a larger person.
b. since kinetic energy depends only on mass, the mass of a person affects Calorie usage.
c. it is easier for a larger person to convert potential energy to kinetic energy.
d. a larger person takes in more Calories per day than a smaller person.
34. Work is something we all do, but which of the following is the most accurate scientific description of work?
a. Work is the result of using a force to move something a specific distance.
b. Work can be measured in newtons.
c. Work can be calculated from the total distance an object is moved regardless of applied force.
d. Work can be related to power by multiplying the work times the seconds that the work was carried out.
35. In which of the following cases is the most power generated?
a. lifting a 10 kg box 1.5 meters
b. lifting a 15 kg box 0.50 meters
c. Both require the same amount of power.
d. This comparison cannot be made without more information.
36. To qualify as a machine, which of the following must be true about using an object to do work?
a. Force out must be less than force in.
b. Force in must be less than force out.
c. Work in must be less than work out.
d. Force in must equal force out.
37. How much distance would you expect to move an object if the machine you were using (such as crowbar or a lever) involved a movement of .010 m from an input of 200 N, but the output force was 500 N? (Ignore any slight thermal energy involved.)
a. Assuming the machine to be ideal, the output distance would be 0.10 m.
b. 0.0040 m
c. 1000 m
d. 0.25 m
38. A machine is going to be used to lift a 1000 N object. Which of the following would be true if the machine is very efficient?
a. Operating the machine would cause a small amount of heat to be lost as thermal energy.
b. The output work would be small compared to the input work.
c. The mechanical advantage would be large.
d. Friction would be very high.
39. A rod, a pivoting rod such as a baseball bat, and a wheelbarrow are all examples of levers. Which of the following is true of a second-class lever?
a. The input force is applied between the output force and the fulcrum.
b. The output force is in the opposite direction from the input force.
c. The output force is exerted between the input force and the fulcrum.
d. The output force is always equal to the input force.
40. Our skeletal and muscle systems make use of some simple machine principles. For example, holding your head up requires force. Which of the following is an accurate comparison of levers and anatomy?
a. Your head and neck act as a first-class lever.
b. Your head and neck act as a second-class lever.
c. Your head and neck act as a third-class lever.
d. Your head and neck act as a fourth-class lever