What is the velocity of the yellow disk after the collision?
Two shuffleboard disks of equal mass, one orange and the other yellow, are involved in an elastic collision. The yellow disk is initially at rest and is struck by the orange disk moving initially to the right at 7.05 m/s. After the collision, the orange disk is at rest.
In a perfectly elastic collision, the final momentum of the bodies that collide is the same as their initial momentum.
Momentum is given as mass*velocity. Let us take the mass of both the disks to be M.
Here, initially the yellow disk is at rest and the orange disk is moving at 7.05 m/s. The total momentum of the two disks is 0*M + 7.05*M.
The collision of the two disks is perfectly elastic and after the collision the orange disk comes to rest. Let the velocity of the yellow disk be V. So the total momentum is M*V + M*0.
Now M*V + M*0 = 0*M + 7.05*M
=> M*V = 7.05*M
=> V = 7.05 m/s
The velocity of the yellow disk after the collision is 7.05 m/s