Question:
An athlete takes 2.0s to reach his maximum speed of 18.0 km/h. What is the magnitude of his average acceleration?
Solution:
$u=0 ; v=18 \times \frac{5}{18}=5 \mathrm{~m} / \mathrm{s} ; \mathrm{t}=2 \mathrm{sec}$
$\mathrm{v}=\mathrm{u}+\mathrm{at}$
$5=0+a(2)$
$\mathrm{a}=2.5 \mathrm{~m} / \mathrm{s}^{2}$