Question

The power, P (watts) , of a car engine is proportional to the square of its speed, s ( m / s ) . When s = 30 , P = 1260 . Work out the power when the speed is 25 m / s

Answer 1

875 Watts

Explanation:

Given that :

P α s²

P = ks²

Where k is the proportionality constant

When ; p = 1260 ; s = 30

1260 = k * 30²

1260 = 900k

k = 1260 / 900

k = 1.4

Value of p ; when s = 25

P = 1.4 * s²

P = 1.4 * 25²

P = 1.4 * 625

P = 875 watt