Answer:
mass of second ball is 0.84 kg
Explanation:
mass of ball = 0.280 kg
to find out
mass of the second ball
solution
we know here elastic head on collision and
second ball moves = half the original speed
we consider here m1 mass of 1st ball and m2 mass of second ball
v1 = velocity of first ball before collision
v2 = velocity of second ball before collision
v3 = velocity of first ball after collision
v4 = velocity of second ball after collision
so here
we know 2nd ball was on rest so v2 = 0
after collision v4 = 1/2 ( v1)
and we know head on collision so
v3 = - v1/2
so from law of conservation of mass
m1v1 + m2v2 = m1v3 + m2v4
put here value
m1v1 + m2(0) = m1(-v1/2) + m2(v1/2)
solve and we get
m2 = 3m1
m2 = 3( 0.280) = 0.84
mass of second ball is 0.84 kg