Question

A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 metric tons (Hint: 1 metric ton = 1000 kg).

Answer 1

Initial velocity, u = 0
Distance travelled, s = 400 m
Time taken, t = 20 s
We know, $s=ut+\frac{1}{2}a{t}^2$
Or, $400=0+\frac{1}{2}a(20{)}^2$
Or, $a=2m{s}^{–2}$
Now, m = 7 MT = 7000 kg, a = 2 $m{s}^{-2}$
Or, F = ma = 7000 $\times$ 2 = 14000 N