Question

A truck start from rest and roll down a hill with a constant acceleration. It travels a distance 400m in 20sec. Find its acceleration. Find the force acting on it if its mass is 7 tonnes.

Answer 1

Answer:-

F = 14,000 N

Given :-

u = 0 m/s

s = 400 m

t = 20 s

m = 7000 kg

To find :-

The acceleration produced and force applied.

Solution:-

Let the acceleration produced in truck be a.

By using 2 nd equation of motion:-

$S = ut + \dfrac{1}{2} at^2$

Put the given values,

→$400 = 0 + \dfrac{1}{2}\times a\times(20) ^2$

→$400 = \dfrac{a}{2}\times 400$

→$400 = 200 a$

→$a = \dfrac{400}{200}$

→$a = 2 m/s^2$

Now,

Force applied on truck will be :-

→$F = ma$

→$F = 7000 \times 2$

→$F = 14,000N$

hence,

Force applied on the truck will be 14,000N.

Answer 2

Solution :

In this Question , We have Provided with the initial velocity of a truck is 0 ( as it start from rest)  and  It travels a distance 400 m in 20 sec and We need to find the acceleration and the force acting on it if its mass is 7 tonnes .

Given ,

u = 0 meter/second

s = 400 meter

t= 20 Second

m = 7 tonnes

⇒ 7000 kg

Finding the acceleration of the body  :

$S = ut + \frac{1}{2} at^2$

⇒ $400 = \frac{a}{2} * 400$

⇒ $400 = 200a$

⇒ $a = \frac{400}{200}$

⇒ $2 m/s^2$

Finding the Force acting on the body :

$F = m * a$

⇒ $7000 * 2$

⇒ $14,000 N$

Therefore , the acceleration of the body is equal to 2$m/s^2$ and the force acting on the body if its mass is 7 tonnes is equal to 14,000 Newton