Conservation of Momentum in a explosion

[mvl46566]

Homework Statement

A firecracker, initially at rest, explodes into two fragments. The first, of mass 14g, moves in the positive x direction at 48m/s. The second moves at 32m/s. Find the mass and direction of its motion.

Homework Equations

p=mv

The Attempt at a Solution

So I know momentum is conserved in this situation. I set m1v1 equal to m2v2 and found the mass of the second fragment to be .041 kg or 41 grams. I think this goes in the negative x direction because the initial momentum is zero and so the sum of all momentums would have to be zero, but I am not sure.

 

[Astronuc]

Homework Statement

A firecracker, initially at rest, explodes into two fragments. The first, of mass 14g, moves in the positive x direction at 48m/s. The second moves at 32m/s. Find the mass and direction of its motion.

Homework Equations

p=mv

The Attempt at a Solution

So I know momentum is conserved in this situation. I set m1v1 equal to m2v2 and found the mass of the second fragment to be .041 kg or 41 grams. I think this goes in the negative x direction because the initial momentum is zero and so the sum of all momentums would have to be zero, but I am not sure.

Correct. In the conservation of momentum, the momentum after the explosion = momentum before the explosion. What is the momentum before the explosion?

Remember that momentum is a vector, which has magnitude and direction. We can have to vectors of the same magnitude, but opposite direction, so the sum is zero.