Work, Energy and Power

Which of the following is NOT an example of work?

• a boy riding a bicycle on the street

• a student walking up a flight of stairs

• the teacher opens the door of the classroom

• someone pushing on a wall of a room in a building

Which of the following statements is NOT true about work?

• Work is a form of energy.

• A kg*m²/s² would be a unit of work.

• Watt is a standard metric unit of work.

• Unit of work would be equivalent to a Newton-meter.

A ball tied to a string is being whirled around in a circle. What can you say about the work done by tension on the string?

• tension does no work at all

• tension does negative work

• tension does positive work

• tension does maximum work

Near the end of the shockwave ride, a braking system exerts an applied force upon the coaster car to bring it to a stop. Determine the work of the indicated force.

• No Work

• Positive Work

• Negative Work

• Maximum Work

In which situation is there work done on the system?

• a basket being lifted

• a weightlifter holding a barbell in the air

• a waiter carrying the order of the customer

• a man carrying a bag of cement on his shoulder

What can be said about the total energy in the universe?

• It tends to decrease.

• It tends to increase.

• It is always zero.

• It is conserved.

What type of energy is illustrated in the position of molecules and electric charges are being altered in using fuel?

• Kinetic energy

• Chemical energy

• Potential energy

• Mechanical energy

What form of energy is present when a bow of an archer is drawn back?

• Kinetic energy

• Chemical energy

• Potential energy

• Mechanical energy

Which of the following possesses elastic energy?

• heating water

• throwing football

• winding the mainspring of a clock

• bicycle coasting along a level road

How much work is necessary to double the speed of a moving object?

• zero work

• same work

• twice the work done

• four times the work done