Question

in an isolated system bicyclist 1 and bicyclist 2 each with a mass of 80 kg, collide. bicyclist 1 was moving to the right at 8 m/s, while bicyclist 2 was moving to the left at 2 m/s. what is the magnitude of their combined momentum before the crash

Answer 1

Consider speed of bicyclist 1 as V1=+8m/s and bicyclist 2 as V2=-2m/s  m=80kg 

Since momentum has opposite signs moving to right or left   

Therefore the combined momentum , P is given by :   

P=m*V1+m*V2 =80*(8-2)kg*m/s=+480 kg m/s