1. a stone is thrown horizontally at 7.5 m/s from
a cliff 87 m high. how far from the base of
the cliff does the stone strike the ground? olom

31.6 m

Explanation:

This situation is a good example of the projectile motion or parabolic motion, in which the travel of the stone has two components: x-component and y-component. Being their main equations as follows:

x-component:

  (1)

Where:

is the stone's initial speed

because we are told the stone is thrown horizontally

is the time since the stone is thrown until it hits the ground

y-component:

  (2)

Where:

 is the initial height of the stone

 is the final height of the stone (when it finally hits the ground)

 is the acceleration due gravity

Finding from (2):

  (3)

  (4)

Substituting (4) in (1):

  (5)

  (6)

Finally: