Imagine we have a 2 lb ball of putty moving 			with a speed of 5 mph striking and sticking to a 18 lb bowling ball 			at rest; the time it takes to collide is 0.1 s. After the collision, 			the two move together with a speed of v1. To 			find v1, use momentum conservation: 2x5=(18+2)v1,			 v1=0.5 mph. Next, imagine we have a 18 lb bowling ball 			moving with a speed of 5 mph striking and sticking to a 2 lb ball of 			putty at rest; the time it takes to collide is 0.1 s. After the 			collision, the two move together with a speed of v2. 			To find v2, use momentum conservation: 			18x5=(18+2)v2, v2=4.5 mph. 
now figure out your problem its really easy let me know if you need more help