What Happens to Velocity and Momentum of a Water-Filled Bucket on Ice?

[ortegavs]

Homework Statement

A bucket full of water is slid across a sheet of ice in the rain. As the bucket fills, what happens to its velocity and its momentum? ( assume no friction)

Homework Equations

P=mv

The Attempt at a Solution

I reasoned that since the bucket gained mass it gained momentum and that since no force acted on the bucket in the horizontal direction v stayed constant.

Answer given: velocity decreases and momentum remains constant
Does this means momentum is a conserved quantity?

 

[pgardn]

Homework Statement

A bucket full of water is slid across a sheet of ice in the rain. As the bucket fills, what happens to its velocity and its momentum? ( assume no friction)

Homework Equations

P=mv

The Attempt at a Solution

I reasoned that since the bucket gained mass it gained momentum and that since no force acted on the bucket in the horizontal direction v stayed constant.

Answer given: velocity decreases and momentum remains constant
Does this means momentum is a conserved quantity?

What would happen if instead, the bucket was moving along at a constant velocity and without interfering with the bucket or the ice, you were able to suck water out of the bucket?

 

[rock.freak667]

The Attempt at a Solution

I reasoned that since the bucket gained mass it gained momentum and that since no force acted on the bucket in the horizontal direction v stayed constant.

Answer given: velocity decreases and momentum remains constant
Does this means momentum is a conserved quantity?

Yes momentum is a conserved quantity.

If initially it has momentum p=m₁v₁

and after it has p=m₂v₂

Then m₂v₂=m₁v₁ or v₂ = (m₁/m₂)v₁

So if m₂ increases then v₂ will decrease.