# Momentum in a Projectile.

## Homework Statement

Is momentum conserved in a projectile? I was a bit confused with this. Would it be conserved only horizontally? What if it explodes at its max height?

mv=mv2

## The Attempt at a Solution

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berkeman
Mentor

## Homework Statement

Is momentum conserved in a projectile? I was a bit confused with this. Would it be conserved only horizontally? What if it explodes at its max height?

mv=mv2

## The Attempt at a Solution

What are your thoughts? What can change momentum?

What are your thoughts? What can change momentum?

ok so lets say some mass at the top of a projectile explodes. The external force on my system(mass) is the force of gravity. During the explosion though, the force of gravity is small enough to ignore it(compared to the explosion). So momentum is conserved in the x and in the y, starting at the top of a projectile. Is it correct to say that?

berkeman
Mentor
ok so lets say some mass at the top of a projectile explodes. The external force on my system(mass) is the force of gravity. During the explosion though, the force of gravity is small enough to ignore it(compared to the explosion). So momentum is conserved in the x and in the y, starting at the top of a projectile. Is it correct to say that?

Gravity is acting on the projectile and the resulting fragments, so that influences the momentum in the y direction both before and after the explosion.

Doc Al
Mentor
ok so lets say some mass at the top of a projectile explodes. The external force on my system(mass) is the force of gravity. During the explosion though, the force of gravity is small enough to ignore it(compared to the explosion). So momentum is conserved in the x and in the y, starting at the top of a projectile. Is it correct to say that?
It's generally a good assumption, considering that the explosive forces are high and short-lived, that other forces such as gravity can be ignored during the explosion. So momentum is conserved during the collision.