Question

A distressed car is rolling backward, downhill at 3.0 m/s when its driver finally manages to

Answer 1

Answer:

Explanation:

Acceleration is equal to the change in velocity over the change in time, or

$a=\frac{v_f-v_i}{t}$ where the change in velocity is final velocity minus initial velocity. Filling in:

$3.0=\frac{v_f-(-3.0)}{6.0}$ Note that I made the backward velocity negative so the forward velocity in our answer will be positive.

Simplifying that gives us:

$3.0=\frac{v_f+3.0}{6.0}$ and then isolating the final velocity, our unknown:

3.0(6.0) = v + 3.0 and

3.0(6.0) - 3.0 = v and

18 - 3.0 = v so

15 m/s = v and because this answer is positive, that means that the car is no longer rolling backwards (which was negative) but is now moving forward.