Question

Two ice skaters approach each other at right angles. Skater A has a mass of 72.3 kg and travels in the +x direction at 2.58 m/s. Skater B has a mass of 60.5 kg and is moving in the +y direction at 0.794 m/s. They collide and cling together. Find the final speed of the couple. Answer in units of m/s.

Answer 1

1.45 m/s

Step-by-step explanation:

This is a conservation of momentum problem (P = mv). Total momentum before the collision must equal total momentum after the collision. Momentum (P) is a vector, so you have to do vector addition to find the resultant momentum (R).

R² = ((72.3 kg)(2.58 m/s))² + ((60.5 kg)(0.794 m/s))²

R² = (186.53 kg·m/s)² + (48.04 kg·m/s)²

R =√34,795 + 2308 =
`√(37101)` = 192.6 kg·m/s

R = mv

v = R/m = (192.6 kg·m/s) / (72.3 kg + 60.5 kg) = 1.45 m/s