How do I find the modulus of the average force of a sphere when it bounces after a collision?

Jun 2017
229
6
Lima, Peru
The problem is as follows:

A sphere of $2\,kg$ is released from a height of $5\,m$ with respect to the ground. After the collision which lasted $0.1\,s$ the sphere bounces with a speed of $5\,\frac{m}{s}$. Find the modulus of the average force in $N$ which the sphere gets from the floor. You may consider that air resistance is negligible and use $g=10\,\frac{m}{s^2}$.

The alternatives given in my book are as follows:

$\begin{array}{ll}
1.&300\,N\\
2.&400\,N\\
3.&320\,N\\
4.&420\,N\\
5.&280\,N\\
\end{array}$

Here I'm totally lost at. The only thing relevant which I can recall is that:

$\vec{J}=\overline{\vec{F}}\Delta t$

But I don't really know how to put the information given into this equation or if it will be relevant in the solution of the problem. Can somebody help me here?.
 

skeeter

Math Team
Jul 2011
3,135
1,698
Texas
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