Question

describe an activity to explain the law of conservation of momentum. A pistol having a mass of 2 kg fires a bullet with a velocity of 150ms`1. if the pistol recoils with a velocity of 1.5ms`1. find the mass of the bullet.

Answer 1

u can get this answer by 3rd law of motion

a similar question is given above

hope it will help you...

Answer 2

According to The Law of Conservation of Momentum" When two or more bodies act upon one another, their total momentum remains constant provided no external force acts on it".

Activity :

Let us make a balloon Rocket.

Apparatus required :

Balloon, Thread, straw and double tape.

Procedure :
 Inflate the balloon and press its neck  with fingers to prevent air escaping from it.

Pass a thread through a straw and tape the bottom end of  balloon to straw.

Hold one end of thread and other end fix to wall.

Now, on releasing the balloon , air comes out from the balloon and balloon moves front

Observation :

Air is allowed to escape from the balloon in backward direction. Due to airs high speed the backward rushing gases high speed and have large momentum . They impart an equal and opposite momentum due to which balloon moves forward with great speed.
Thus we can say that Balloon or Rocket /Jetplanes works on the principle of law of conservation of momentum "

Problem :

mass of piston=2kg
velocity of bullet=150m/s
recoil velocity of pistol=1.5m/s
mass of bullet =?
Momentum of bullet=momentum of Pistol
mass of bullet x velcoity of bullet = Recoil velocity of pistol and mass of pistol
mass of bullet=1.5x2/150
=0.02kg

Therefore mass  of bullet is 0.02kg