Question

Two skaters on in-line skates, A and B, are initially at rest. They push apart and start moving in opposite directions. If A's speed just after they push apart is 3.0 m/s and mass of A is 75% of B's mass, how fast is B moving at that time?​

Answer 1

Answer:

Given,

Initial velocity, u

1

=0andu

2

=0

Mass,m

1

=60kgandm

2

=40kg

Final Velocity, v

1

=2ms

−1

From conservation of momentum

Final momentum = initial momentum

m

1

v

1

+m

2

v

2

=m

1

u

1

+m

2

u

2

60×2+40v

2

=0

v

2

=−3ms

−1

Hence, velocity of second skater is −3ms

−1