# Calculate momentum of the puck

• rrosa522
In summary: Your answer is correct.In summary, the hockey player imparts an impulse of 0.75 kg*m/s to the puck with a force of 250N and a contact time of 0.0030s. The resulting momentum of the puck is also 0.75 kg*m/s due to the collision. However, if the puck was at rest before being hit, the momentum would be 4.2 kg*m/s. The relationship between impulse and momentum is important in understanding collisions.
rrosa522

## Homework Statement

A hockey player passes a puck with an average force of 250N. The hockey stick is in contact with the puck for 0.0030s, and the mass of the puck is 180g. The puck is not moving before the player hits it.

a) Determine the impulse imparted by the hockey stick.
b)Calculate the momentum of the puck as a result of the collision

p=mv

## The Attempt at a Solution

I got 0.75 kg*m/s for the part A but I don't know what to do for part B. Shouldn't the answer be the same for both. I really don't understand the difference between both questions.

rrosa522 said:
I really don't understand the difference between both questions.
They want to see if you understand the relationship between impulse and momentum. Sounds like you do.

rrosa522 said:
Shouldn't the answer be the same for both.
Yes, in this case. But what if the puck was at rest when it was hit?

Doc Al said:
They want to see if you understand the relationship between impulse and momentum. Sounds like you do. Yes, in this case. But what if the puck was at rest when it was hit?
how can I find the momentum without knowing the velocity, the answer should be 4.2kg*m/s

rrosa522 said:
how can I find the momentum without knowing the velocity,
You know the impulse, which is all you need. Review the impulse-momentum theorem.

rrosa522 said:

Doc Al said:
You know the impulse, which is all you need. Review the impulse-momentum theorem.Why do you think that? Your initial answer was correct.
yes, but the answer in my book is 4.2. I just want to know if it is a mistake.

rrosa522 said:
yes, but the answer in my book is 4.2. I just want to know if it is a mistake.
Looks to me like the book is mistaken.

## 1. How do you calculate the momentum of a puck?

The momentum of a puck can be calculated by multiplying its mass (m) by its velocity (v). The formula for momentum is: p = m * v.

## 2. What units are used to measure momentum?

Momentum is measured in units of kilogram-meters per second (kg*m/s).

## 3. Can the momentum of a puck change?

Yes, the momentum of a puck can change if its mass or velocity changes. The greater the mass or velocity, the greater the momentum.

## 4. How does friction affect the momentum of a puck?

Friction can decrease the momentum of a puck by slowing it down. This is because friction acts in the opposite direction of the puck's motion, causing it to lose some of its velocity.

## 5. What is the importance of calculating momentum in sports like hockey?

Calculating momentum in sports like hockey can help players and coaches understand the power behind a shot or the force of a collision on the ice. It can also help with strategizing and making decisions during a game.

• Introductory Physics Homework Help
Replies
3
Views
2K
• Introductory Physics Homework Help
Replies
3
Views
3K
• Introductory Physics Homework Help
Replies
4
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
3K
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
7
Views
4K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
21
Views
2K
• Introductory Physics Homework Help
Replies
35
Views
4K