A mass m1 15.0 kg traveling East at 12.0 m/s undergoes an elastic, head on, collision with a mass m₂ traveling West at 14.0 m/s.
After the collision mı is traveling West at 10.0 m/s. What was the mass of m₂?
a. 5.00 kg
b. 82.5 kg
c. 7.50 kg
d. 11.0 kg