Question

A bullet of mass 5 g strikes a wooden plank of thickness 5 cm at 350 m/s and emerges out at 150 m/s. The average frictional force acting on the bullet when it was inside the plank is?
Give explanation with solution.​​

Answer 1

Answer:

-5000N

Explanation:

Mass of the bullet(m) = 5g = 0.005kg

Initial Velocity (u) = 350m/s

Final Velocity (v) = 150m/s

Displacement through the plank (S) = 5cm = 0.05m

⇒ v² - u² = 2aS

⇒ (150)² - (350)² = 2 * 0.05 * a

⇒ a = (22500 - 122500)/ 0.1

⇒ a = -100000/0.1

⇒ a = -1000000

We know that,

F = ma

  = 0.005 * -1000000

  = -5000N

I do hope that this helps you, mate!