Elastic collisions of a sliding block

[intenzxboi]

1. Homework Statement [/b]
Block 1, with mass m1 and speed 3.6 m/s, slides along an x-axis on a frictionless floor and then undergoes a one-dimensional elastic collision with stationary block 2, with mass m2 = 0.69m1. The two blocks then slide into a region where the coefficient of kinetic friction is 0.39; there they stop. How far into that region do (a) block 1 and (b) block 2 slide?



I used the elastic collision formula and got v1f= .6604m/s and v2f=4.260 m/s

can i use conservation of ke?? to find mass?

 

[LowlyPion]

1. Homework Statement [/b]
Block 1, with mass m1 and speed 3.6 m/s, slides along an x-axis on a frictionless floor and then undergoes a one-dimensional elastic collision with stationary block 2, with mass m2 = 0.69m1. The two blocks then slide into a region where the coefficient of kinetic friction is 0.39; there they stop. How far into that region do (a) block 1 and (b) block 2 slide?

I used the elastic collision formula and got v1f= .6604m/s and v2f=4.260 m/s

can i use conservation of ke?? to find mass?

You can determine the distance by observing the deceleration of the friction for each block and applying it to the velocity.

F = m*a = μ*m*g

a = μ*g