A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 ms–2 for 8.0 s.

Solution:
Given, initial velocity of boat, u = 0
Acceleration, $\mathrm{a}=3.0 \mathrm{~m} \mathrm{~s}^{-2}$
Time, $\mathrm{t}=8 \mathrm{~s}$
Distance covered, $\mathrm{s}=$ ?
Using the relation $\mathrm{s}=\mathrm{ut}+\frac{1}{2} \mathrm{at}^{2}$ we have,
$\mathrm{s}=0 \times 8+\frac{1}{2} \times 3 \times 8^{2}=96 \mathrm{~m}$