How Do You Calculate Change in Momentum Without Mass?

AI Thread Summary
To calculate the change in momentum without knowing the mass of the ball, focus on the concept of momentum per unit mass, which is equivalent to the velocity. The problem specifically asks for momentum per unit mass, so you can directly use the recorded velocity values from your experiment. The sign of the velocity is important and depends on your chosen direction for positive values; if the ball is falling downwards, it would typically be negative. Thus, the change in momentum per unit mass can be determined by analyzing the velocity data collected during the impacts. Understanding these principles will allow you to solve the problem effectively.
amanda.ka
Messages
46
Reaction score
0

Homework Statement


I did an experiment where I dropped a ball beneath a motion sensor and it recorded the vertical components of position vs time, velocity vs time, and acceleration vs time.
The question asks to determine the change in the ball's linear momentum (per until mass) during the 5 selected impacts with the ground. I know that the equation for linear momentum is p = (mass)(velocity) however the experiment did not say to weigh the ball so I do not have "m". How would I go about solving this? Also I know that momentum is a vector quantity so the sign is important. Does that mean my velocity values would be negative as the ball is falling towards the ground? Thanks in advance!

Homework Equations


p = mv

The Attempt at a Solution

 
Physics news on Phys.org
amanda.ka said:

Homework Statement


I did an experiment where I dropped a ball beneath a motion sensor and it recorded the vertical components of position vs time, velocity vs time, and acceleration vs time.
The question asks to determine the change in the ball's linear momentum (per until mass) during the 5 selected impacts with the ground. I know that the equation for linear momentum is p = (mass)(velocity) however the experiment did not say to weigh the ball so I do not have "m". How would I go about solving this?
Note that the problem didn't ask you for the momentum but the momentum per unit mass.

Also I know that momentum is a vector quantity so the sign is important. Does that mean my velocity values would be negative as the ball is falling towards the ground? Thanks in advance!
This depends on your sign convention. Which direction do you want to call the positive direction? If the ball's velocity is in that direction, it would be positive; if it's in the opposite direction, it would be negative.

Homework Equations


p = mv

The Attempt at a Solution

 
vela said:
Note that the problem didn't ask you for the momentum but the momentum per unit mass.

Does this mean that the linear momentum would just be equal to the velocity?
 
Yes, the momentum per unit mass is just the velocity.
 
  • Like
Likes amanda.ka

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Ambiguous question on momentum and how it works...
Replies
13
Views
1K
Linear and angular momentum problem: Ball hitting a rod
2
Replies
62
Views
12K
Angular and Linear Momentum Problem
Replies
18
Views
3K
Golf club 🏌️and ball ⛳ impulse problem
Replies
19
Views
2K
How Does Impulse Relate to Momentum Change in Physics Problems?
Replies
7
Views
2K
Momentum: instantaneous or average?
Replies
9
Views
1K
How Does Angular Momentum Conservation Affect Asteroid Collision Dynamics?
7
Replies
335
Views
14K
About linear and angular momentum
Replies
12
Views
2K
Work done during a collision -- Change in Kinetic Energy & change in Momentum
Replies
1
Views
2K
Change in momentum when given the speed (not the velocity).
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top