Title: 1.3 The distinction between energy and power

A heavy block is lifted 3 meters in the air. This task requires approximately 300 J of work.

Q: 1. How long does this take with a motor and pulley which has a power output of 5 W?

          [...] seconds

2. How long does this take if the pulley system has a power output of 100 W?

          [...] seconds
A: 60; 3
Feedback (0 to 100%): 1 W = 1 J/s, therefore the required time is E/p. (300J / 5 J/s and 300J / 100J/s)

A roller coaster is lifted to a height of 24 m within 30 seconds. This task requires around 360 · 10³ J of energy.

Q: 1. How many kilowatts of power does the system lifting the roller coaster has to deliver at least?

          [...] kW
A: 12
Feedback (0 to 100%): p = E / t, therefore it is 360'000J/30s which is 12'000J/s and equal to 12kW.

Q: Alicia decides to buy a new car and is confused whether or not she wants a car with a large engine, or a car with a large fuel tank. Which corresponds to increased energy, and which corresponds to increased power?
- A large fuel tank corresponds to increased energy capacity (i.e. more fuel = more energy in the car), and a large engine corresponds to a more powerful engine. (correct)
- A large fuel tank corresponds to increased power (i.e. more fuel = more power to the engine), and a large engine corresponds to more energy in the vehicle.

Q: Mainly, Alicia likes to take fast leisure drives on sunny days, racing down the autobahn. What kind of car should she pick for this purpose?
- A car with a large, powerful engine. (correct)
- A car with a smaller engine, but considerable fuel tank.