Question

When an automobile moves with constant velocity, the power developed in a certain engine is 60.5 hp. What total frictional force acts on the car at 72.3 mi/h ? 1 hp = 746 W and 1 m/s = 2.2374 mi/h. Answer in units of N.

Answer 1

Step-by-step explanation:

Given

Power delivered by engine
`P=60.5\ hp`

`1\ hp=746\ W`

`P=60.5\ hp\approx 45,133\ W`

velocity of automobile
`v=72.3\ mi/h`

`1\ m/s=2.2374\ mi/h`

`v=32.31\ m/s`

Power delivered is given by

`P=force* velocity`

`Force=friction\ force`

`45,133=f\cdot 32.31`

`F=1396.87\ N`