Water Bucket Momentum Question

In summary, when a bucket full of water is slid across a sheet of ice in the rain, its velocity decreases and its momentum remains constant. This is because the bucket gains mass as it fills with water, resulting in a decrease in velocity. However, since there is no external force acting on the bucket, its momentum remains constant. This also means that momentum is a conserved quantity, as shown by the equation P=mv. If water is removed from the bucket without interfering with the bucket or the ice, the velocity will decrease and momentum will remain constant, following the equation v2 = (m1/m2)v1.
  • #1
ortegavs
13
0

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?
 
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  • #2
ortegavs said:

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?
 
  • #3
ortegavs said:

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.

ortegavs said:
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.
 

1. What is the water bucket momentum question?

The water bucket momentum question is a physics problem that involves understanding the concept of momentum and how it applies to a system of water buckets. In this scenario, a person is standing on a frictionless surface with a bucket of water in each hand. They then throw the water from one bucket into the other. The question is, what happens to the person's overall momentum?

2. How is momentum defined?

Momentum is defined as the product of an object's mass and velocity. In other words, it is a measure of how difficult it is to stop an object's motion. The larger an object's mass and/or the faster it is moving, the greater its momentum.

3. What is the initial momentum of the person in the water bucket momentum question?

The initial momentum of the person in the water bucket momentum question is zero. This is because the person is initially at rest on a frictionless surface, so their velocity is zero. The buckets of water also have zero momentum since they are not moving.

4. What happens to the person's momentum after they throw the water from one bucket to the other?

After the person throws the water from one bucket to the other, their overall momentum will still be zero. This is because the person and the buckets of water have equal and opposite momentums. When the water is thrown, the person's momentum decreases in one direction while the buckets' momentum increases in the opposite direction, resulting in a net momentum of zero.

5. How does the water bucket momentum question relate to Newton's third law of motion?

The water bucket momentum question is a practical application of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. In this scenario, the action is the person throwing the water, and the reaction is the change in momentum of the person and the buckets of water. This law helps to explain why the person's overall momentum remains zero in this situation.

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