Physics, asked by kunalnitinpatil, 9 months ago

two balls of masses 200 gram and 150 gram are moving with velocity 18m/s and 20m/s towards each other . after collision bigger ball moves with velocity 12m/s in its initial direction. find velocity of smaller ball.

Answers

Answered by Cosmique
13

Given :

  • Mass of bigger ball, m₁ = 200 g = 0.20 kg
  • Mass of smaller ball, m₂ = 150 g = 0.15 kg
  • Initial velocity bigger ball, u₁ = 18 m/s
  • Initial velocity of smaller ball, u₂ = -20 m/s

( since balls are moving toward each other so velocity of one ball must be taken negative )

  • Final velocity of bigger ball after collision, v₁ = 12 m/s

To find :

  • Final velocity of smaller ball after collision , v₂ = ?

Knowledge required :

  • Law of conservation of momentum

During the collision between two bodies the total momentum before collision is equal to the total momentum after collision of the bodies. this law is known as law of conservation of momentum.

m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂

[ Where m₁ and m₂ are masses of two bodies ,u₁ and u₂ are initial velocities of bodies and v₁ and v₂ are final velocities of bodies ]

Solution :

Using law of conservation of momentum

→  m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂

→  (0.20) (18) + (0.15) (-20) = (0.20) (12) + (0.15) v₂

→ 3.6 - 3.0 = 2.4 + 0.15 v₂

→ 0.6 = 2.4 + 0.15 v₂

→ 0.6 - 2.4 = 0.15 v₂

→ -1.8 = 0.15 v₂

→ v₂ = ( -1.8 ) / 0.15

v₂ = -12 m/s

therefore,

  • Ball will move with a velocity of -12 m/s after collision.

( Negative sign describe that ball will move in its initial direction of motion ).

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