The power, P (watts) , of a car engine is proportional to the square of its speed, s ( m / s ) . When s = 15 , P = 2100 . Work out the speed (to 1 DP) when the power is 2200 watts

The speed of the car engine is 15.4m/s

Step-by-step explanation:

Given

Power = 2100; when Speed = 15

Required

Find Speed when Power = 2200

The question says power is proportional to square of speed;

Mathematically;

Represent Power with P and Speed with S

Convert proportion to an equation

Where k is proportionality constant

Make k the subject of formula

When P = 2100 and S = 15

When P = 2200 and S is unknown

Recall that

So;

becomes

Cross Multiply

Divide both sides by 2100

Take Square Roots of both sides

(Approximated)

i think it is c, not positive though

step-by-step explanation: