Answer:
8 kg.
Explanation:
Remember that the formula to calculate the kinetick energy is half of the mass mutiplied by the squared velocity:
[tex]Ke= .5mv^2[/tex]
So in order to solve this problem we will have to solve the equation for mass:
[tex]M=\frac{324J}{.5*81} \\m=\frac{324}{40.5}\\ m=8 kg[/tex]
So by clearing the equation you now know that the answer is that there are 8 kg in an object that is moving at 9m/s and has a kinetic energy of 324J.
