Question

A rock is thrown horizontally from a tower at a speed of 10 m/s and it lands 20.0 m from the tower's base.
a) How high is the tower?
b) What is the final velocity of the rock

Answer 1

The rock moves at a constant speed horizontally and falls freely vertically. So it takes 2.0 seconds to reach the ground. Using \[y = v _{0} t + \frac{ 1 }{ 2 }a t ^{2}\]you can work out how high the tower is.
For question b, you can use \[v=v_{0} + at\]