Question

A ball of mass 0.5kg is dropped from a height. Find the work done by it weight in 1sec after the ball is dropped

Answer 1

here's your answer acceleration is taken 9.8 m/s²

Answer 2

Answer:

24.01 J.

Explanation:

Given that the mass of the ball, m = 0.5 kg.

The work done by a uniform force F in displacing an object to a displacement d is given by

W = Fd.

The force that acts on the ball, while it drops is its own weight, i.e., F = mg.

where, g is the acceleration due to gravity, having value $\rm 9.8\ m/s^2.$

The only acceleration with which the ball moves is g.

Therefore, the diplacement covered by the ball in time t = 1 second is given by the following equation:

$\rm d = ut+\dfrac 12 at^2.$

where, u is the initial speed of the ball and since the ball is dropped from a height, therefore, its initial velocity is zero, i.e., u = 0 m/s.

Putting all the values,

$\rm d = 0\times 1+\dfrac 12 g\times 1^2=\dfrac{g}{2}.$

Thus, the work done by the weight of the ball in 1 second after it has dropped is given as:

$\rm W = Fd\\\\=(mg)(\dfrac g2)\\\\=\dfrac{mg^2}{2}\\=\dfrac{0.5\times 9.8^2}{2}\\=24.01\ J.$