Question

A 2kg ball rolls down a frictionless ramp of height 5m, at the end of the ramp what will its velocity be?

Answer 1

We will have the following:

First, we will determine the gravitational potential energy, that is:

$U=(2kg)(9.8m/s^2)(5m)\Rightarrow U=98J$

Now, we calculate the kinetic energy at that stage:

$\begin{gathered} K=U \\ \\ \Rightarrow98J=\frac{1}{2}(2kg)v^2\Rightarrow v^2=98m^2/s^2 \\ \\ \Rightarrow v=7\sqrt{2}m/s\Rightarrow v\approx9.9m/s \end{gathered}$

So, the velocity of the ball is 7sqrt(2) m/s, and that is approximately 9.9 m/s.