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 tonnes (Hint: 1 tonne = 1000 kg.)​

Answer 1

14000 N

Explanation:

=> Initial velocity of the truck, u = 0

=> Distance covered by the truck, s = 400 m

=> Time taken to cover that distance, t = 20 s

Let the acceleration of the truck be a

=> s = ut + 1/2at²

=> 400 = (0)20 + 1/2a(20)²

=> a = 2 m/s²

Mass of the truck,

=> M = 7 tonnes = 7000 kg

( ∵ 1 tonne = 1000 kg)

=> F = Ma = 7000 x 2 = 14000 N