Question

An earthmover slows from 42.0 km/h to 4.00 km/h in 4.75 s. What is its rate of acceleration in m/s2

Answer 1

acceleration (a) = change in velocity / change in time

Δv = final velocity - initial velocity = 4 km/h - 42 km/h = -38 km/h

Δt = 4.75 s

convert km/h to m/s

-38/ 3.6 = -10.56 m/s

a = -10.56 m/s / 4.75 s = -2.23 m/s^2