Power (T4)

Question 1

In physics how do we define power?

Answer 1

Power is defined as the rate of doing work.

This means that the power dissipated during an energy conversion process is equal to the amount of energy converted per second.

Question 2

What is the equation for calculation power?

Answer 2

P = W / t

P = power in watts
W = work done or energy converted in joules
t = time in seconds

Question 3

1 horsepower is equivalent to how many watts?

Answer 3

1 horsepower = 746 watts

Question 4

Describe an experiment to measure your output power..

Answer 4

1) weigh yourself (W, Newtons)
2) measure the height of one step on a flight of stairs (s, metres)
3) count the number of steps (n)
4) time how long it takes to climb the stairs (t, seconds)

Work done climbing the stairs
= F x d
= W x n x s

Power = work / time

Power = Wns / t