Question

A car is moving at 30 ft/sec when the brakes are applied. It decelerates at a constant rate of 5 ft/sec2 until it stops. If t = 0 represents the time at which the brakes are applied, how far will it go before stopping?

Answer 1

The distance traveled by car before stopping is
`90\, ft`

Step-by-step explanation:

Given

Initial speed of car
`u=30\, (ft)/(sec)`

Final speed of the car
`v=0\, (ft)/(sec)`

Acceleration of the car
`a=-5\, (ft)/(sec^(2))`

Let distance traveled before stopping be s

Using equation of motion

`v^(2)=u^(2)+2as`

=>
`0^(2)=30^(2)+2* (-5)* s`

=>
`s=90\, ft`

Thus the distance traveled by car before stopping is
`90\, ft`