Tied mass with angular velocity

Click For Summary
The discussion focuses on a physics problem involving a ball tied to a thread, moving in a circular path on a smooth horizontal plane. A force of 0.8 Newtons is applied to draw the thread, maintaining a radius of 0.4 meters, while a larger force of 4 Newtons is later applied to reduce the radius to 0.1 meters. Participants are asked to calculate the work done by Harry and the work done by the ball during this process. The calculations require understanding the relationship between force, distance, and work in a circular motion context. The thread seeks assistance in solving these physics equations.
Hafid Iqbal
Messages
15
Reaction score
0
http://img221.imageshack.us/img221/522/fisikaumn.jpg
A small ball (mass = 0,1 kg) tied to a non-stretchable thread moves over a smooth horizontal plane. The other end of the thread is being drawn into a hole O with a 0,8 Newton force so that the ball moves with a constant radius 0,4 m
And then Harry pull the thread with a constant force 4 Newton so that the ball moves come near to hole O until its radius is 0,1 m

a. Work done by Harry = ... J
b. Work done by that ball = ... J

Thank you very much
 
Last edited by a moderator:
Physics news on Phys.org
Anyone? :(
 
Thread 'Correct statement about size of wire to produce larger extension'
The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...

Similar threads

Replies
14
Views
3K
  • · Replies 2 ·
Replies
2
Views
799
Replies
10
Views
2K
Replies
335
Views
15K
  • · Replies 32 ·
2
Replies
32
Views
2K
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
Replies
38
Views
3K
Replies
3
Views
3K