A stone thrown horizontally from a height of 5.72 m hits the ground at a distance of 13.30 m. Calculate the initial speed of the stone. Neglect air resistance.

initial velocity=12.31 m/s

Final speed = 16.234 m/s

Explanation:

Given Data

height=5.72 m

distance=13.30 m

To Find

Initial Speed=?

Solution

Use the following equation to determine the time of the stone is falling.

d = vi * t ½ * 9.8 * t²

Where

d = 5.72m and vi = 0 m/s

so

5.72 = ½ * 9.8 * t²

t = √ (5.72 : 4.9)

t=1.08 seconds

To determine the initial horizontal velocity use the following equation.

d = v*t

13.30 = v * 1.08

v = 13.30 : 1.08

v=12.31 m/s

To determine stone's final vertical velocity use the following equation

vf = vi+9.8*t ... vi=0 m/s

vf = 9.8*1.08

vf = 10.584 m/s

To determine stone's final speed use the following equation

Final speed = √[Horizontal velocity²+Final vertical velocity²]

Final speed = √{ (12.31 m/s) ² + (10.584 m/s) ²}

Final speed = 16.234 m/s