Question

A ball of mass 100g moving with velocity with 10m/s . Calculate the force applying by the boy to stopped the ball ​

Answer 1

Questions :

A ball of mass 100g is moving with a velocity 10m/s is stopped by a boy in 0.2 seconds. Calculate the force applied by the boy to stop the ball.

Given :

• Mass of the ball = 100 g

• Initial Velocity = 10 m/s

• Time of applied force = 0.2 s

Solution :

To find the force, we need the Acceleration and the mass of the body.

Here, we are provided with the mass , so let's determine the value of the acceleration.

To find the acceleration of the ball :

Using the First Equation of Motion and substituting the values in it, we get :

$\boxed{\bf{v = u + at}}$

Where :

• v = Final Velocity
• u = Initial Velocity
• a = Acceleration
• t = Time Taken

$:\implies \bf{0 = 10 + a \times 0.2}$

$:\implies \bf{-10 = 0.2a}$

$:\implies \bf{-10 = \dfrac{2}{10}a}$

$:\implies \bf{-10 \times 10 = 2a}$

$:\implies \bf{-100 = 2a}$

$:\implies \bf{-\dfrac{100}{2} = a}$

$:\implies \bf{-50 = a}$

$\boxed{\therefore \bf{Acceleration\:(a) = - 50\:ms^{-2}}}$

Hence, the acceleration produced is -50 m/s².

To find the Force exerted :

First let us the convert the mass of the body from g to kg (SI unit of mass).

We know that ,

1 kg = 1000 g

So , 100 g = 100/1000 kg

→ 0.1 kg

Hence, the mass of the ball in kg is 0.1 kg.

We know the formula for force, i.e,

$\boxed{\bf{F = ma}}$

Where :

• F = Force exerted
• m = Mass of the body
• a = Acceleration

Now , using the above formula and substituting the values in it, we get :

$:\implies \bf{F = ma}$

$:\implies \bf{F = 0.1 \times (-50)}$

$:\implies \bf{F = -5}$

$\boxed{\therefore \bf{Force\:(F) = -5\:N}}$

Hence, the force exerted by the ball is -5 N.