Q. 54.5( 190 Votes )

# 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).

Answer :

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* + a*t*^{2}

400 = 0 × 20 + × a × (20)^{2}

400 = 0 + × a × 400

400 = a × 200

a =

a = 2 m/s^{2}

Therefore, the acceleration of the truck is 2 m/s^{2}

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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