Question

A force act up a body of mass of 20 kg ,initially at rest for 6s after which the force ceases, now the body describe 60 m in next 5s .find the magnitude of force.

Answer 1

To Find :-

• The magnitude of force.

Solution :-

Given,

• Mass of the body (m) = 20 kg
• Initial velocity of body (u) = 0 ms-¹
• Distance (s) = 60 m

As we know that,

Velocity = Distance / Time

Here,

• Velocity = Final velocity of the body.

[ Put the values ]

↪ Final velocity = 60/5

↪ Final velocity = 12 ms-¹

Applying newton's 1st equation of motion,

v = u + at

[ Put the values ]

↪ 12 = 0 + a × 6

↪ 12 = 6a

↪ a = 12/6

↪ a = 2 ms-²

By newton's 2nd law of motion,

F = ma

[ Put the values ]

↪ F = 20 × 2

↪ F = 40 N

Therefore,

The magnitude of force is 40 N.