Question

A siege machine was a device used to throw large rocks at castle walls. A particular siege engine was located 100m from its target and launched projectiles at an angle 30° from the ground. How fast must the projectile be moving at launch to ensure it does hit the ground in front of the wall(Assume the ground is flat, the projectile is launched from ground level and g=9.8 m/s²)

Answer 1

The distance between the launch point and the wall is 100 m. Therefore the range is R = 100 m

Angle of launch is

The range is given by

Therefore the velocity of the launch is