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

Explanation

First of all we find its accelrating by using the relation:
Distance travelled,s=ut+`1/2at^(2)`
Here,Distance travelled, s =400 m
Initial speed, u=0 (It starts from rest)
Time, t = 20 s
and Acceleration, a=? (To be calculated)
Putting these values in the above formula, we get :
`400=0xx10+1/2xxaxx(20)^(2)`
400=200a
`a=400/200`
Acceleration,a=2m/`s^(2)`
We will now calculate the force by using the relation: .....(1)
F=`mxxa`
Here Mass, m =7 metric tonnes
`=7xx1000 kg` ....(2)
And, Acceleration, a = 2 m/`s^(2)` (Calculated above)
So, Force, F = `7000 xx 2`
F=14000 N
Thus, the force acting on the truck is 14000 newtons.