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 if its mass is 7 tonnes ( Hint: 1 tonne = 1000 Kg)

Answer 1

given data,

Initial velocity $=u=0$

Distance $=s=400m$

time $=t=20sec$

$a=$ acceleration

We know that,

Equation of motion:-

$s=ut+\frac{1}{2}a{t}^2$

$400=0+\frac{1}{2}\times a\times 20\times 20$

$400=200a$

$a=2$

acceleration $=a=2m/s^2$

Force $=F=?$

The force acting on the mass is $7$ tonnes$(\therefore 1tonne=1000Kg)$

Mass $m=7\times 1000=7000Kg$

Mass $=m=7000kg$

Acceleration $=a=2m/s^2$

$F=ma$

$=7000\times 2$

$=14000N$

Force acting on it is $14000N$