Answer to Question #101829 in Mechanics | Relativity for Chisom

Question

A gun of mass 2.0kg fired a bullet of mass 0.02kg wit d velocity of 15o/m, calculate d kinetic energy of d gun and kinetic energy of d bullet. Formula =1/2x mass x velocity.

Answer 1

Given:

$m_1=2.0\:\rm kg;$

$m_2=0.02\:\rm kg;$

$v_2=150\:\rm m/s;$

The speed of the gun after shot

$$v_1=\frac{m_2v_2}{m_1}=\frac{0.02\times 150}{2.0}=1.5\:\rm m/s$$

Hence, the kinetic energy of the gun:

$$E_1=\frac{m_1v_1^2}{2}=\frac{2.0\times 1.5^2}{2}=2.25\:\rm J$$

The kinetic energy of the bullet:

$$E_2=\frac{m_2v_2^2}{2}=\frac{0.02\times 150^2}{2}=225\:\rm J$$