Question

3 pts


A bullet moving with a velocity 100ms strikes a wooden Planck it penetrates the Planck to depth of 20cm before coming to stop calculate average retardation of the bullet while passing through planck

Answer 1

initial speed, u = 100 m/s

final speed, v = 0

distance travelled in plank, s = 20 cm = 0.2 m

acceleration, a = ?

 

we know that v² - u² =2as

⇒ 0 - 100² = 2×a×0.2

⇒ -10000 = 0.4a

⇒ a = -10000/0.4

⇒ a = -25000 m/s²

Retardation is 25000 m/s².