Question

Two skaters collide and grab on to each other on frictionless ice. One of them, of mass 77.0 kg, is moving to the right at 4.00 m/s, while the other, of mass 66.0 kg, is moving to the left at 2.50 m/s.
What is the magnitude of the velocity of these skaters just after they collide?
What is the direction of the velocity of these skaters just after they collide?
a. to the left
b. to the right

Answer 1

Answer:3.31m/s², to the right

Explanation:

According to the law of conservation of momentum of a body, change in momentum of bodies before collision is equal to the change in momentum after collision.

Momentum = mass × velocity

M1 and M2 be the masses of the first and second skaters respectively

Let u1 and u2 be the velocities of the first and second skaters respectively.

v be their common velocity after collision

M1 = 77kg M2 = 66kg u1 = 4m/s² u2 = 2.5m/s²

According to the law we have

M1u1 + M2u2 = (M1+M2)v

77(4) + 66(2.5) = (77+66)v

308 + 165 = 143v

V = 473/143

V = 3.31m/s²

Their velocity after collision will become 3.31m/s²

They will both move towards the right after collision because the mass of the body moving to the right is higher than the other mass and the mass is also moving at a higher velocity than the other.