Question

I am traveling at 100 m/s, I hit the brakes and my speed goes down to 50 m/s. It took 30 seconds to slow down. What was my acceleration?

A.5 m/s2
B.-5 m/s2
C.1.7 m/s2
D.-1.7 m/s2

Answer 1

D. -1.7m/s2

Step-by-step explanation:

the car starts at 100m/s so this is the initial velocity. It ends at 50m/s so this is the final velocity. it took 30 seconds so the time is 30.

`v_(f)=v_(i)+at`

`a=(\left(v_(f)-v_(i)\right))/(t)`

`a=\ (\left(50-100\right))/(30)`

`a=-1.66666666667`
`m/s^(2)`

Therefore, the answer is D