Question

Question 5&6:

5. A ball of mass 1 kg dropped from 9.8 m height, strickes the ground and rebounds to a height of 4.9 m. If the time of contact between ball and ground is 0.1 s, then find impulse and average force acting on ball.

6. A machine gun fires a buillet of mass 50 gm with velocity 1000 m/s. If average force acting on gun is 200 N then find out the maximum number of bullets fired per minute.

Answer 1

Dear Student,

$$\begin{gathered} iniyialmomentum \\ u=\sqrt{2*9.8*9.8}=9.8\sqrt{2}m/s \\ {p}_i=mu \\ v=\sqrt{2*9.8*4.9}=9.8m/s \\ {p}_f=-mv \\ impulse=p_f-p_i=-mv-mu=-\left(9.8+9.8\sqrt{2}\right)=-23.66kgm/s \\ force=\frac{-23.66}{0.1}=-236.66N \\ Regards \end{gathered}$$