Question

If you drop a 2.2kg ball from the top of a 42m high building, how fast will it be going just before it hits the ground? Round to the nearest tenth and include the appropriate unit

Answer 1

Given

This is a free fall problem where we have information about the mass, initial velocity and initial height of the object.

m = 2.2 kg

h = 42m

g = 9.8m/s2

vo = 0 m/s

The data given were: mass, height, initial velocity and gravity, which is already known.

Procedure

to solve this problem we rely on the free fall equations as follows.

`\begin{gathered} v_f^2=v_o^2+2gh \\ v_f=√(2gh) \end{gathered}`

This equation relates the final velocity to the initial velocity, gravity and height.

Using the above equation and replacing the values we can proceed to calculate.

`\begin{gathered} v_f=\sqrt{2*(9.8m)/(s^2)*42m} \\ v_f=28.7m/s \end{gathered}`

The final velocity would be 28.7 m/s