Question

Graph of tension in the string with time?

Answer 1

@Mashy @DLS

Answer 2

What do you think?
Have you already ruled out any possibilities?

Answer 3

Yes.
Tension wont remain constant obviously. So (1) is ruled out.
Tension wont be 0 is at any point either, so (3) can be ruled out too.
Now the thing i wanted to confirm is at the end points, the velocity will be 0 right? So the tension would be just T=mgcos(theta) and at the bottom most position it would be T=mg+mv^2/l . And in between the equilibrium position and the end points it varies proportional to 1/l . So the answer would be (4).
I realised this after posting the question though.

Answer 4

@yrelhan4 3g dekhli?movie?

Answer 5

LOL nhi.

Answer 6

:/

Answer 7

You are right. 4 is the answer.

Answer 8

Am i right about the tension at the extreme points? T=mgcotheta?

Answer 9

Tension at a string varies at every point. I thought it increases uniformly,if we had a simple mass attached,then it would be directly propotional right?

Answer 10

Only if the string has mass.
If the string is massless, then tension is constant at every point.

Answer 11

Uniformly thing?

Answer 12

What uniformly? If the string has mass it has different tension at each points.

Answer 13

weird :/

Answer 14

Later. :/

Answer 15

:/

Answer 16

Quote: "Am i right about the tension at the extreme points? T=mgcotheta?"

Answer: True, since angular velocity is zero there.

Solving N's 2nd law yields:

\(T=mg\cos \theta + m\,l\,\dot \theta ^2\)

Answer 17

Thank you. :)