Question

A 55-kg skater moving at 2.5 m/s overtakes a 45-kg skater moving at 1.0 m/s in the same direction and collides with her. The two skaters stick together. What is their final speed?

Answer 1

1.825m/s

Step-by-step explanation:

Using the law of conservation of momentum which says that momentum before collision is equal to sum of momentum after collision.

m1u1+m2u2 = (m1+m2)v

m1 and m2 are the masses

u1 and u2 are the initial velocities

v is final velocity of the two bodies after collision

Substitute the given parameters into the formula

55(2.5)+45(1) = (55+45)v

137.5+45 = 100v

182.5 = 100v

v = 182.5/100

v = 1.825m/s

Hence their final speed is 1.825m/s