Question

When a driver presses the brake pedal, his car stops with an acceleration of -2.1 m/s2. How far will the car travel while coming to a complete stop if its initial speed was 13 m/s?

Answer 1

The kinematic equation that will be used for this problem is:
Vf^2 = V1^2 + 2 * a * d, where, 
Vf = final velocity = 0 m/s
V1 = initial velocity = 13 m/s
a = acceleration = -2.1m/s^2
d = distance traveled = ?
Inserting the given values, the equation becomes
0^2 = 13^2 + 2 * -2.1 * d
0 = 169 + - 4.2*d
169 = 4.2 * d
169/4.2 = d = 40.24
Therefore, d = 40.24 M.