Anand Ratna M. answered 11/15/21
My Expertise in (Electrostatic, Calculus, Algebra, Trigonometry)
In this question given mass of bullet 18g and block mass m = 1.3kg , coefficient of surface kinetic friction is s = 0.36 and block traveled before stopped are = 9.5m
First we calculate deceleration then calculate speed of bullet and block then apply conservation of momentum and find initial velocity of bullet which is equal to nozzle speed .
For deceleration we can say that ma = smg
a = sg = a = 0.36 x 10
a = 3.6 m/s2
Hence use kinametics equation v2 = u2 + 2ax
Where v is final velocity and u is initial velocity.
02 = u2 -2 x 3.6 x 9.5 u2
u2 = 68.4 = u = 8.27 m/s
This is combined speed of block and bullet hence apply conservation of momentum.
Initial momentum. = Final Momentum
18×10-3 x v = ( 0.018+ 1.30) x 8.27
v = 605.54 m/s. Answer.