Answer:
Mass of the second ball is 0.84 kg
Step-by-step explanation:
The collision is said to be elastic collision when the kinetic energy of the system remains conserved after the balls collides. The momentum of the system is also conserved.
The mass of the first ball is m₁ = 0.280 kg
We have to the find the mass of second ball m₂.
Let
initial velocity of first ball be u₁
initial velocity of second ball is u₂ =0
mass of second ball is m₂
Final velocity of second ball is 0.5 u₁
As the collision is elastic
u₂-u₁ = v₂-v₁
0-u₁ =0.5 u₁-v₁
v₁ = -0.5 u₁
According to law of conservation of momentum,
m ₁u₁+m₂u₂=m₁v₁+m₂v₂
0.280*u₁+m₂*0=0.28* -0.5 u₁+m₂*0.5 u₁
0.28 u₁ +0.14 u₁ = 0.5u₁m₂
m₂= 0.84 kg
The mass of the second ball is 0.84 kg.