A 28-g bullet pierces a sand bag that is 30 cm thick. The initial speed of the bullet is 55 m/s and it emerged from the sandbag at speed 18m/s. What is the average magnitude of the friction force that slowed the bullet as it traveled through the bag?
Conserving mechanical energy of the system
Work done by frictional force = change in kinetic energy
F*0.3 = 75.628
average magnitude of frictional force = F = 252.094N