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 tonnes (Hint. 1 metric tonne = 1000 kg).


Firstly, we will calculate the acceleration:

Given,


Initial velocity, u = 0


Distance travelled, s = 400 m


Time, t = 20 s


Acceleration, a =?


We know that,


s = ut + at2


400 = 0 × 20 + × a × (20)2


400 = 0 + × a × 400


400 = a × 200


a =


a = 2 m/s2


Therefore, the acceleration of the truck is 2 m/s2


Now, we will calculate the force:


Force, F = m × a


F = 7 × 1000 × 2


= 14000 N


Therefore, the force acting on the truck is of 14000 N


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