Question

A motorcyclist sees a branch in the road, and hits the brakes, slowing down at -6.42 m/s^2. If it takes him 2.85 s to stop, what was his starting velocity?

Answer 1

Answer:

his starting velocity was 18.297 ms⁻¹

Explanation:

v = u + at .................. (1)

Where

Final Velocity (v) = 0 ms⁻¹

Initial velocity (u) = ?

Acceleration (deceleration) (a) = -6.42 ms⁻²

time (t) = 2.85 s

Substituting all parameters into equation (1)

0 = u + (-6.42)2.85

0 = u + (-18.297)

0 = u - 18.297

18.297 = u

∴ the initial velocity was 18.297 ms⁻¹