1. The problem statement, all variables and given/known data Two objects collide on a horizontal frictionless surface. Object 1 comes from the left with mass .753kg and initial velocity of -.28m/s collides with object 2 moving from the right with an unknown mass and an initial velocity of .28m/s. They stick together when collided and moved to the right. The final velocity of object 1 is .2121m/s and velocity of object 2 is .292m/s. Find mass of object 2. 2. Relevant equations M1V01+M1V02=M1Vf1+M2Vf2 M1(Vf1-V01)/V02-Vf2=M2 3. The attempt at a solution I have attempted this and got an answer of 30.879 as the mass but the correct answer was .648kg. I'm not sure which step I'm doing wrong because I have gone over several times and see if it was just algebra mistake but it wasn't and still got a really big number. Could someone give some pointers what I'm doing wrong?