Watts

What is the difference between watts and watt-hours?

• Watts measure power, while watt-hours measure energy.

• Watts and watt-hours are the same unit of measurement.

• Watts are used for electricity, while watt-hours are used for other forms of energy.

• Watts measure energy, while watt-hours measure power.

The SI unit for power is

• meters

• mass

• kilograms

• watts

The SI Unit for Power

• Newton (N)

• Joule (J)

• Second (s)

• Watt (W)

What is the formula for Power?

• E=mc²

• W= F x d

• P = W/t

W = 500 Joules 
t = 25 seconds
P = ???

• 0.05 W

• 20 W

• 12500 W

• 2000 W

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts

• 3 watts

• 120 watts

• 270 watts

While rowing across the lake during a race, John does 3960 J of work on the oars in 60 seconds. What is his power output?

• 56W

• 100W

• 66W

• None of the answers are correct

A horse performs 15,000 joules of work pulling a wagon for 20 seconds. What is the horse's power?

• 750 W

• 300 W

• 2.25 J

In just one second, a certain coal-fired power plant produces enough electricity to do 900 J of work. What is the power output of this power plant?

• 1 W

• 833 W

• 66 W

• 900 MW

If it takes 50 seconds and 10 Joules move some books, calculate how much power is required to complete this task.

• 5 J

• 0.2 W

• 5 W