Conservation of momentum
200*10 + 20*4 = 200*v
2000 + 80 = 200v
2080 = 200v
v = 10.4 m/s
Total time = 10/4 = 2.5sec
S = 2.5*10
S = 25m
A trolley of mass 200kg moves with a uniform speed of 36km/h on a frictionless track.A child of mass 20kg runs on the trolley from one end to the other ,10m away,with a speed of 4 m/s relative to the trolley in a direction opposite to its motion,and jumps out of the trolley.What is the final speed of the trolley?How much has the trolley moved from the time the child begins to run??
Conservation of momentum
200*10 + 20*4 = 200*v
2000 + 80 = 200v
2080 = 200v
v = 10.4 m/s
Total time = 10/4 = 2.5sec
S = 2.5*10
S = 25m