Question

Projectile Motion

A rifle is fired horizontally and travels 200m East. The rifle barrel is 1.90m from the ground. What speed must the bullet have been traveling at? Ignore Friction.

Answer 1

First, the motion in the x direction is as simple as x=v*t; so you know that your speed is x/t, or 200/t.
In the y direction you have acceleration, so you need x=v*t+a*t^2
the distance traveled in the y direction is 1.90m (you got x), the velocity is 200/t( you got v, the acceleration is gravity ( you got a), the only thing left is to solve for time, and after that come back to the initial equation v=x/t, and that's it
:)