Question

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

Answer 1

MgVg=MbVb.

4×Vg=0.05×35.

4Vg=1.75.

Vg=1.75/4

=0.4375 ~ 0.4m/s.

Answer 2

`\large{\bf{\gray{\underline{\underline{\orange{Given:}}}}}}`

Mass of rifle = 4kg

Mass of bullet = 50g = 0.05kg

Initial velocity of bullet = 35m/s

`\large{\bf{\gray{\underline{\underline{\green{To\:Find:}}}}}}`

Recoil velocity of rifle.

`\large{\bf{\gray{\underline{\underline{\pink{Solution:}}}}}}`

Recoil velocity of rifle is given by

`\dag\:\boxed{\bf{\purple{V=-(mv)/(M)}}}`

• M denotes mass of rifle
• m denotes mass of bullet
• v denotes velocity of bullet

`:\implies\sf\:V=-(mv)/(M)`

`:\implies\sf\:V=-(0.05* 35)/(4)`

`:\implies\sf\:V=-(1.75)/(4)`

`:\implies\bf\:V=-0.437\:ms^(-1)`

[Note : -ve sign shows opposite direction]