a bullet of mass20g traveling horizontaly with speed of 500m/s passes through a wooden block of mass10kg initially at rest on alevel surface.the bullet rmerges with a speed of 100m/s andthe block slides20cm on thr surface brfore coming to rest. fiend the friction coefficirnt between the block and the surface

 the ans is 3.2

use netwon second law of motion.draw fbd of the diagram. then equate all horitzonal foce(x axis )to ma.then then equate all vertical force to zero(y axis).then simple the given equation.afther  that equate, use  usN=froce(f).then find us(coffient) of friction in it........... that it sipmle to do.....try it until y get....