Question

If the car’s speed decreases at a constant rate from 64 mi/h to 30 mi/h in 3.0 s, what is the magnitude of its acceleration, assuming that it continues to move in a straight line? What distance does the car travel during the braking period?

Answer 1

Answer:
`3.874 m/s^2`

Step-by-step explanation:

Given

Car speed decreases at a constant rate from 64 mi/h to 30 mi/h

in 3 sec

`60mi/h \approx 26.8224m/s`

`34mi/h \approx 15.1994 m/s`

we know acceleration is given by
`=(velocity)/(Time)`

`a=(15.1994-26.8224)/(3)`

`a=-3.874 m/s^2`

negative indicates that it is stopping the car

Distance traveled

`v^2-u^2=2as`

`\left ( 15.1994\right )^2-\left ( 26.8224\right )^2=2\left ( -3.874\right )s`

`s=(488.419)/(2* 3.874)`

s=63.038 m