- #1

- 7

- 0

## Homework Statement

Mass 1 (2.77 kg) moves with an initial velocity (1i - 1j) and mass 2 (1 kg) starts at rest. After the collision, M2 moves with a velocity of (2i - 3j). What is the final velocity of m1?

## Homework Equations

Since they don't stick together, KE and linear momentum are conserved.

M1V1ix + M2V2ix = M1V1fx + M2V2fx

M1V1iy + M2V2iy = M1V1fy + M2V2fy

1/2 M1V1i^2 + 1/2M2V2i^2 = 1/2 M1V1f^2 + 1/2M2V2f^2

V1f = (sqrt)V1xf^2 + V1yf^2

## The Attempt at a Solution

I don't really understand these problems, and we had a substitute professor in to teach this, so here goes nothing, literally.

2.77 (1) + 0 = 2.77 Vx + 1(2) Vx = 0.278 m/s ????

2.77(-1) + 0 = 2.77 Vy + 1(-3) Vy = 0.0.83 m/s ?????

This doesn't seem right? Shouldn't I need to use th equations for KE for an elastic collision?