Question

A 710 kg car drives at a constant speed of 23 m/s. It is subject to a drag force of 500 N. What power is required from the car's engine to drive the car

a) on level ground?

b) up a hill with a slope of 2.0°?

Answer 1

Step-by-step explanation:

Given that,

Mass of the car, m = 710 kg

Speed of the car, v = 23 m/s

Drag force, F = 500 N

(a) Let P is the power is required from the car's engine to drive the car on the level ground. Power is given by :

`P=F* v\\\\P=500\ N* 23\ m/s\\\\P=11500\ W`

(b) Let P is the power is required from the car's engine to drive the car on up a hill with a slope of 2 degrees.

At this slope, force will be,
`F=mg\ \sin\theta`

Total force will be :

`F=710* 9.8* \sin(2)+500\\F=742.83\ N`

Power is given by :

`P=F* v\\\\P=742.83* 23\\\\P=17085.09\ W`

or

P = 17 kW