Question

The power, P (watts), of a car engine is proportional to the square of its speed, s(m/s) When s= 30 P= 1500 Work out the speed (to 1 DP) when the power is 1715 watts

Answer 1

S = 32.1 m/s

Explanation:

P = 1,500

S = 30

since P is proportional to S², then we must first determine S² = 900

900 / 1,500 = S² / 1,715

(900 x 1,715) / 1,500 = S²

1,543,500 / 1,500 = S²

S² = 1,029

S = √1,029 = 32.08 m/s ≈ 32.1 m/s