Question

A small puck with a mass of 0.10 kilograms is sliding in the +x-direction on an air table with an initial speed of 8.0 meters/second. The puck collides with a larger puck that is initially at rest. The larger puck has a mass of 0.40 kilograms. After the collision, the smaller puck has a speed of 3.4 meters/second at an angle of +60° from its original path. The angle made by the larger puck is -35°. What is the x-momentum after the collision if the velocity of the larger puck after the collision is 1.5 meters/second?

0.8 kilogram meters/second
1.5 kilogram meters/second
2.1 kilogram meters/second
3.6 kilogram meters/second
4.8 kilogram meters/second

Answer 1

other guys right, the answer is 0.8 kilogram meters/second

i got 100 on the test

Answer 2

By definition we have the momentum is:
p = m * v
Where
p: linear momentum
m: mass
v: speed.
For this case, momentum is conserved!
initial x momentum = 0.1kg * 8m / s = 0.8kg · m / s = final x-momentum
All the rest is clutter.
the answer is
0.8 kilogram meters/second