Answer to Question #109512 in Electricity and Magnetism for dfd

Question

A cannonball with a mass of 13.1 kg is fired from a cannon that has a mass of 907.2 kg. The cannonball is fired with a speed of 159.4 m/s, and it takes 0.0 seconds for the cannonball to leave the cannon.



Determine the recoil speed of the cannon.

Answer 1

mass of cannonball $m_1=13.1$ kg

mass of cannon $m_2=907.2$ kg

velocity of cannonball $v_1=159.4$ m/s

Lets write conservation law of momentum: $0=m_1v_1-m_2v_2$

where $v_2$ is recoil speed of the cannon.

Then $v_2=v_1 {\frac {m_1} {m_2}}=2.3$ m/s