An indestructible bullet 2.27 cm long is fired
straight through a board that is 8 cm thick.
the bullet strikes the board with a speed of
401 m/s and emerges with a speed of 265 m/s.
what is the average acceleration of the bullet through the board?
answer in units of m/s
2

Explanation:

We can assume that the bullet decelerates only when it is passing through the board, from the moment it starts touching the board until it leaves it completely; so, it accelerates for a total distance of

d = 2.27 cm + 8 cm = 10.27 cm = 0.103 m

So we can use the following equation to find its acceleration:

where

v = 265 m/s is the final speed of the bullet

u = 401 m/s is its initial speed

a is the acceleration

d = 0.103 m

Solving for a,

the independent variable, or the one that is intentionally manipulated is the speed.

there are no components of a physical goal mentioned on the list of choices that you've provided.