Question

A car moving at 15 m/s north needs to stop in 100 m. What acceleration is required? Round answer to nearest whole number.

a. + 2 m/s2
b. - 1 m/s2
c. 0 m/s2
d. -15 m/s2

Answer 1

Step-by-step explanation:

We know that,

Distance(S)= 100 m

Initial velocity (u)= 15 m/s

Final velocity (v) = 0m/s [As the car stops at last]

We know that,

`2aS=v^2-u^2`

`a= (v^2-u^2)/(2S) \\`

Substitututing values for v,u,S we get,

`a=(0^2-15^2)/(2*100) \\a=(-225)/(200) \\a=-1.125\\Approxiametly, -1 (to the nearest whole number)`