Question

A ball of mass 200g is moved with 20m/s and decrease to 10m/s in 5s due to air friction so force of friction due to air is

Answer 1

Answer:-

Newton's 3rd Law of Motion: Every action has an opposite and equal reaction which acts on both the objects.

∴ The air will also provide the same magnitude of force to the ball. But the symbol would be (- ve).

Given:-

• m = 0.2 kg
• u = 20 m/s
• v = 10 m/s
• t = 5 s

We know,

F = ma

where,

• F = Force,
• m = Mass &
• a = Acceleration.

Also,

a = (v - u)/t

where,

• v, u = Final and Initial velocities respectively,
• t = Time taken.

Thus,

F = m(v - u)/t

→ F = (0.2 kg)[(10 - 20) m/s]/5 s

→ F = (0.2 kg)(- 10 m/s)/5s

→ F = (0.2 kg)(- 2 m/s²)

→ F = - 0.4 kg m/s²

→ F = - 0.4 N

(Force acting on the body at the opposite side of it's motion.)

Thus, air provided a force of 0.4 N.