A rifle is aimed horizontally at a target 50 m away. The bullet hits the target 2.4 cm below the aim point.

Part A

What was the bullet's flight time? Neglect the air resistance
Part B

What was the bullet's speed as it left the barrel?

1 answer

In the absence of air resistance we can split the movement of the bullet into the vertical and horizontal components.

The former is a free-fall.
Using the kinematics equation below, we can solve for the time it takes to free-fall through 2.4 cm:
S=(v0)t+(1/2)at^2
with
v0=initial (vertical) velocity = 0
a=acceleration due to gravity=-9.81 m/s^2
s=-0.024 m
solve for t to get
t=sqrt(2*0.024/9.81)=0.07 s

If the bullet covered 50m in 0.07s, you can calculate the bullet's muzzle speed, in m/s.