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

 

[nlightner]

I can confirm that you can use the conservation of kinetic energy to find the mass of the blocks in this scenario. In an elastic collision, the total kinetic energy before and after the collision remains the same. Therefore, you can use the equation 1/2mv^2 to find the mass of the blocks by plugging in the final velocities obtained from the elastic collision formula. However, it is important to note that the mass of block 2 is already given as 0.69m1 in the problem statement. So, you can use this equation to verify your results or to cross-check your calculations. As for finding the distance the blocks slide, you can use the equations of motion and the given information about the coefficient of kinetic friction to calculate the distance traveled by each block. I hope this helps!