Work, Energy and power

Open Ended

What invisible property allows a roller coaster to climb, a jet engine to roar, and a weightlifter to break records?

Open Ended

Why is energy considered the fundamental ability for objects to produce change in themselves or the world around them?

Open Ended

If you push against a solid brick wall with all your strength for an entire hour and it doesn’t move a single millimeter, how much physics 'Work' have you done?

Open Ended

If the star does no work on the planet, why does the planet keep moving? (Hint: Think about Newton’s First Law and whether the speed is actually changing).

Open Ended

When a catcher’s mitt stops a 90mph fastball, negative work is done on the ball. Where does that ‘spent’ energy go?

Multiple Choice

Which of the following statements best describes the relationship between work and energy as shown in the Work-Energy Theorem?

• Work is unrelated to energy changes.

• Work increases or decreases the energy of a system.

• Work only decreases the energy of a system.

• Work only increases the energy of a system.

Multiple Choice

If a car simply doubles its speed, how many times greater does its Kinetic Energy become?

• Twice as great

• Four times as great

• Eight times as great

• Half as great

Open Ended

In the real world, the roller coaster eventually comes to a stop without brakes. If energy cannot be destroyed, what happened to the 40,000 J?

Multiple Choice

Who produced more power: Lifter A or Lifter B, given they both lifted the same 100 kg barbell but Lifter A took 2 seconds and Lifter B took 4 seconds?

• Lifter A

• Lifter B

• Both produced the same power

• Not enough information

Open Ended

Explain how the concept of power output can be applied to compare the energy usage of a washing machine, a sprinter, and a jet engine.

Multiple Select

Which of the following are considered useful energy outputs in the efficiency calculation shown?

• Useful light

• Useful sound

• Wasted heat

• Total input

Open Ended

If the tomato fell through a vat of thick honey instead of air, would it still hit the bottom at 5.83 m/s? Use the concepts of conservation and 'work done by friction' to explain.

Open Ended

Summarize one new thing you learned about energy from today's lesson. How might this knowledge help you understand the world around you?