Question

A ball of mass 500 g is moving with a velocity of 50 m s-1. The ball is brought to rest by applying a constant force for 0.2 s. Calculate the force applied.

Answer 1

Given :

• Final velocity (v) = 0 m/s
• Initial velocity (u) = 50 m/s
• Time (t) = 0.2 seconds
• Mass (m) = 500 g [ In kg : 0.5 ]

To find :

• Force

According to the question,

At first we have to find acceleration then we will calculate the force applied.

→ v = u + at

Where,

• v stands for Final velocity
• u stand for Initial velocity
• t stands for Time
• a stands for Acceleration

Substituting the values,

→ 0 = 50 + a (0.2)

→ 0 - 50 = 0.2a

→ - 50 = 0.2a

→ - 50 ÷ 0.2 = a

→ - 250 = a

∴ The acceleration is -250 m/s²...

As we know that,

→ Force = Mass × Acceleration

Or,

→ F = ma

Substituting the values,

→ F = 0.5 × -250

→ F = -125 N

So,the force applied is -125 N. It means that the force is acting on opposite direction.