Question

2.

A body at rest has mass 10kg. It is moved by a horizontal force of SN on a horizontal surface. Calculate the work done by the force in 8s.

Answer 1

Answer:

80kg simple

Explanation:

yes it is simple

Answer 2

Answer:

The work done by 5N of force in 8s is 80J.

Explanation:

The work done is the product of the force exerted and the displacement caused due to it.

If the force exerted

F = 5N

The mass of the body is given as

m = 10kg

Since Force = mass × acceleration,

Acceleration caused by the force

a = $\frac{Force}{mass}$

  = $\frac{5N}{10kg}$

a  = 0.5 $ms^{-2}$

The body is initially at rest. Hence, initial velocity

u = 0 $ms^{-1}$

We have to calculate the work done in

t = 8s

The displacement caused due to the exerted force can be calculated using the second equation of motion,

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

  = 0 × 8 + $\frac{1}{2}$ × 0.5 × 8²

s = 16m

Now, the work done can be calculated using

W = F × s

   = 5 × 16

Work done by a force of 5N on a mass of 10kg at rest through 8s

W = 80J