Question

An athlete takes 2.0 s to reach his maximum speed of 18.0 km/h. What is the magnitude of this average acceleration.

Answer 1

Initial velocity, u = 0
Final velocity, v = 18 km/h = 5 m/s
Time interval, t = 2 s
Using $v=u+at$, we get:
$\mathrm{Acceleration}=a_{av}=\frac{\left(v-u\right)}{2}=\frac{5}{2}=2.5\mathrm{m}/{\mathrm{s}}^2$