Question

A bullet of.mass 50g moving with velocity 600m/s hits a block of mass 1kg placed on a rough horizontal ground and comes out of th block with a velocity of 400m/s. The coefficient of friction between the block.and the ground is 0.25. Neglect loss of.mass of the.block as the bullet pierces through it.
(a) Inspite of frictional force, can.we apply conservation of momentum.
(b) Find the velocity of block immediately after the bullet pierces through it.
(c) find the distance the block will.travel before it stops.

Answer 1

Dear Student,
$$\begin{gathered} \left(a\right)Yes,wecanapplyconservationofmomentum. \\ b)byconservationofmomentum \\ 50\times {10}^{-3}\times 600+0=(1.050)V \\ V=\frac{50\times {10}^{-3}\times 600}{1.050}=28.57m/s \\ c)Lossinkineticenergyofbullet=workdonebyblocktotravelonthesurface \\ \frac{1}{2}\times .05\times (600{)}^2-\frac{1}{2}\times .05\times (400{)}^2=.25\times 1.050\times 10\times d \\ d=1904.76m \end{gathered}$$
Regards