Question

A wooden trolley of mass 3 kg is mounted on wheels on horizontal rails.Neglecting friction and air resistance,what will be the final velocity of the trolley if a bullet of mass 2 gm is fired into it with a horizontal velocity of 800 m/s along the dirction of the rails

Answer 1

Answer:

Since the hole is on the floor , that means sand is falling vertically with respect to trolley. Therefore there is no force in horizontal direction hence in horizontal direction momentum is conserved.

Let M= mass of trolley

m= mass of sandbag

v

1

= initial velocity

v

2

= final velocity ( to be found)

Then P

1

=(M+m)v

1

when the sand bag is empty the momentum is

P

2

=(M+0)v

2

Momentum is conserved in horizontal direction so

P

1

=P

2

⇒=v

2

=

M

(M+m)

v

1

=

300

300+25

×27×

18

5

=8.215m/s