Solve Energy Word Problem: Find Height Swinging Rope w/ 3.5 m/s Vel

AI Thread Summary
A student running at 3.5 m/s grabs a hanging rope and needs to determine how high they can swing. The conservation of mechanical energy principle is key, where the initial kinetic energy converts to potential energy at the maximum height. The student initially struggles with the problem but realizes that at the point of grabbing the rope, all energy is kinetic, transitioning to potential energy at the peak. After some guidance, the student successfully finds the answer, indicating a better understanding of the concepts involved. The discussion emphasizes the importance of grasping energy conservation in solving such physics problems.
Thenewbie
Messages
2
Reaction score
0

Homework Statement



A student is running at a speed of 3.5 m/s and grabs a long rope that is hanging vertically from the ceiling. How high can the student swing?


Homework Equations



For what we're learning right now, we should be using:
PEi + KEi = PEf + KEf

The Attempt at a Solution



I don't even know where to start. What possible formula can help me find this answer with only the initial velocity?

PS. The answer is provided, but I am trying to figure out just HOW to do this. Thanks to somebody who can explain or guide in the right path...
 
Physics news on Phys.org
hmm that's strange when we did the law of conservation of mechanical energy there was never a question with only one variable given. I am pretty sure that question is impossible unless they expect you somewhere to assume a variable. Check that its not apart of a bigger question or a series of questions that references the other variables that you require.
 
I'd consider using conservation of energy.

At the point he grabs the rope, he has all kinetic energy and no potential energy. By the time the rope reaches its maximum height, it has no kinetic energy and all potential energy.

It's at least a mental starting point for you to try, as long as you know the expressions for kinetic and potential energy.
 
whybother said:
I'd consider using conservation of energy.

At the point he grabs the rope, he has all kinetic energy and no potential energy. By the time the rope reaches its maximum height, it has no kinetic energy and all potential energy.

It's at least a mental starting point for you to try, as long as you know the expressions for kinetic and potential energy.

AHH! Thank you thank you! I just got the answer, wow, don't know why I didn't see it before. Our teacher went through this material really fast, so I'm still trying understand it all a little better.

Thanks for all your help!
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Conservation of Energy -- Object around a loop
Replies
10
Views
3K
Conservation of energy: Crane raising a mass
Replies
17
Views
3K
Starting height of marble rolling around a loop the loop
Replies
12
Views
12K
Maximum height of CM of a rotating stick
Replies
3
Views
2K
Draw a FBD, calculate tension in the string, determine mass
Replies
8
Views
3K
Why do I not get the same result when I use change in PE?
Replies
3
Views
2K
Kinetic and Potential energy problem
Replies
11
Views
3K
How High Does a Swing Reach After Pumping Stops?
Replies
1
Views
2K
Down an Incline with Spring: Finding Distance and Maximum Speed
Replies
1
Views
4K
Going down a slide CONSERVATION OF ENERGY
Replies
3
Views
4K

Hot Threads

Recent Insights

Back
Top