Below are some carefully selected power word problems to help you understand the concept of power in physics.
Problem # 1:
How much power is required to do 200 joules of work in 4 seconds?What if you do the same work in 2 seconds? Did you notice anything? Say what you noticed.
I noticed that more power is required to do the same work in less time.
Problem # 2:
Which person is more powerful?
It takes John 2 seconds to lift a 100-kg barbell a distance of 20 centimeters.
It takes Peter 3 seconds to lift a 200-kg barbell a distance of 15 centimeters.
First, convert 20 centimeters and 15 centimeters to meters.
20 centimeters = 0.20 meters and 15 centimeters = 0.15 meters.
Find the force that is required to lift 100 kg and 150 against gravity.
F = 100 × 10 = 1000 Newtons
F = 200 × 10 = 2000 Newtons
Problem # 3:
The power of a machine is 4 kilowatts. How much work can this machine do in 1 second ? Answer should be in Newtons/ 4 meters. Don't use the formula to solve this problem!If you still cannot do it without using the formula, click here to see the solution.