Arock thrown horizontally from a bridge. show that the height of the bridge hits the water below. the rock travels in a smooth parabolic path in time. show that is 1/2gt^2

This situation is related to parabolic motion and the main equation is:

  (1)

Where:

is the final height of the rock, asuming the top of the bridge touches the surface of the water

 is the initial height of the rock

is the vertical component of the initial velocity (it is zero because the rock was thrown horizontally)

is the time the parabolic motion lasts

 is the acceleration due gravity

Rewritting (1) with these conditions:

  (2)

Hence:

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement