Kinetic energy of a rolling hoop

AI Thread Summary
To stop a 120 kg hoop rolling at 0.240 m/s, the total kinetic energy (KE) must be calculated, which includes both translational and rotational components. The calculation yields a total KE of 6.912 J. It's recommended to adjust the significant digits in the final result to align with the precision of the given data. Additionally, for clarity in a "show your work" assignment, it's beneficial to explain that the total KE equals the work required to stop the hoop. Proper presentation of calculations enhances understanding and accuracy in physics problems.
Jrlinton
Messages
133
Reaction score
1

Homework Statement


A 120 kg hoop rolls along a horizontal floor so that its center of mass has a speed of 0.240 m/s. How much work must be done on the hoop to stop it?

Homework Equations


I of hoop=MR^2

The Attempt at a Solution


KE=0.5*m*v^2+0.5*(mR^2)(v/R)^2
=0.5*120kg*.24^2m/s+0.5*(120kg*R^2)(.24m/s^2/R^2)
=6.912 J

.
 
Physics news on Phys.org
Your calculation looks good. You might want to trim the significant digits in your result to match the given data. If this is a "show your work" type question rather than a web based "enter the solution" assignment, you might want to include a note as to why the total KE is the same as the work required.
 

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 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »
Thread 'A bead-mass oscillatory system problem'

Thread 'A bead-mass oscillatory system problem'

I can't figure out how to find the velocity of the particle at 37 degrees. Basically the bead moves with velocity towards right let's call it v1. The particle moves with some velocity v2. In frame of the bead, the particle is performing circular motion. So v of particle wrt bead would be perpendicular to the string. But how would I find the velocity of particle in ground frame? I tried using vectors to figure it out and the angle is coming out to be extremely long. One equation is by work...
View full post »

Similar threads

How Is Potential Energy Converted to Kinetic Energy in Physical Systems?
Replies
6
Views
1K
Why Is Deriving the Motion Formula for Hoops More Complex?
Replies
4
Views
1K
Moment of inertia problem involving a cylinder rolling down an incline
Replies
11
Views
2K
Kinetic Energy of a Cylinder Rolling Without Slipping
Replies
21
Views
4K
Total kinetic energy for rolling hoop
Replies
2
Views
5K
Earth's rotation slows down slightly over time -- How much energy is lost?
Replies
15
Views
2K
Frequencies of Small Oscillations for a Hoop Rolling in a Pipe
Replies
7
Views
3K
A bead rests at the top of a fixed, frictionless hoop.
Replies
44
Views
9K
What linear speed must a 0.0500-kg hula hoop have if its total kinetic energy
Replies
3
Views
6K
Finding slip-off angle for mass off of sphere?
Replies
7
Views
1K

Hot Threads

Recent Insights

Back
Top