A bullet 2cm log is fired at 420m/s and passes straight a 10cm thick board exiting at 280m/s

Complete question:

A bullet 2 cm long is fired at 420m/s and passes straight through a 10.0 cm thick board, exiting at 280m/s? What is the average acceleration of the bullet through the board?

The average acceleration of the bullet through the board is -4.083 x 10⁵ m/s²

Explanation:

Given;

initial velocity of the bullet, u = 420 m/s

final velocity of the bullet, v = 280 m/s

length of the bullet, d₁ = 2 cm

thickness of the board, d₂ = 10 cm

total distance penetrated by the bullet through the board;

d = d₁ + d₂ = 2 cm + 10 cm = 12 cm = 0.12 m

The average acceleration of the bullet through the board is calculated as;

Therefore, the average acceleration of the bullet through the board is -4.083 x 10⁵ m/s²

they should be similar or the same

real, smaller and upside-down.   so the answer should be b.