Question

A projectile is shot at an angle of `pi/4` and a velocity of `21 m/s`. How far away will the projectile land?

Answer 1

The projectile will land 45 m downfield, assuming it was launched over level ground.

Explanation:

Rather start from scratch (meaning the equations of motion) to solve this one, I will use an equation that can be derived for the range `R` of a projectile:

`R=v_o^2/gsin 2theta`

where `v_o` is the launch speed and `theta` is the launch angle.

Now it is a simple matter of putting values in place of variables:

`R=21^2/9.8 sin (pi/2) = 45 m`