Question

A wooder trolley of man's 3kg is mounted on wheels on hocizontal racts.Neglecting friction and air resisitance,what will be the final velocity of the trolley if a bullet of mess 2gm is fired into it with a horizontal velocity of 800m/s along the direction of the rails.

Answer 1

Answer:

Explanation:

Mass of the trolley, M=200kg

Speed of the trolley, v=36km/h=10m/s

Mass of the boy, m=20kg

Initial momentum of the system of the boy and the trolley

=(M+m)v

=(200+20)×10

=2200kg m/s

Let v ′ be the final velocity of the trolley with respect to the ground.

Final velocity of the boy with respect to the ground =v′−4

Final momentum =Mv ′+m(v ′−4)

=200v′+20v ′ −80

From the conservation of linear momentum:

Initial momentum= Final momentum

2200=220v′ −80

V" =2280/220=10.36m/s

Length of the trolley, l=10m

Speed of the boy, v"=4m/s

Time taken by the boy to run, t=10/4=2.5s

∴ Distance moved by the trolley =v"×t

= 10.36×2.5=25.9m