Question

From rifle of mass 4kg , a bullet of mass 50g is fired with an initial velocity of 35m/s . Calculate the initial recoil velocity of the rifle​

Answer 1

Answer:

The initial recoil velocity of the rifle. Initially, the rifle is at rest. The negative sign indicates that the rifle recoils backwards with a velocity of 0.4375 m/s.

Answer 2

Answer:

$\mathrm{Mass \: of \: rifle,M= \: 4 \: kg } \\ \mathrm{Mass \: of \: bullet,m = \: 50g} \\ \rightarrow \mathrm {\frac {50}{1000}g = 0.05kg}$

$\mathrm {Velocity \: of \: bullet,v = 35m/s}$

$\mathrm {Velocity \: of \: rifle,V = ?}$

•According the the law of conservation of momentum :-

momentum of rifle = momentum of bullet

$\rightarrow \mathrm {MV = mv}$

$\rightarrow \mathrm {4kg×V = 0.05×35}$

$\rightarrow \mathrm {V = \frac{ 0.05×35}{4}}$

$\rightarrow \mathrm {V = \frac{1.75}{4}}$

$\rightarrow \mathrm {V = \frac{1.75}{4}}$

$\purple {\rightarrow \boxed {\mathrm {V = - 0.4375m/s}}}$

Therefore, Recoil velocity, V, of rifle is -0.4375m/s.

HOPE IT HELPS YOU DEAR.. ;)