How Does Young's Modulus Factor into Calculating Pendulum Swing Velocity?

[Abhishekdas]

Young's modulus question...

Homework Statement

A sphere of radius 10 cm and mass 25 kg is attached to the lower ends of a steel wire which is suspended from the ceiling of a room. the point of the support is 521 cm above the floor. When the sphere is set swinging as a simple pendulum, its lowest point just grazes the floor. Calculate the velocity of the ball at its lowest point.

Homework Equations

The Attempt at a Solution

I think some information is missing here...Either th strain or the initial length or change in length should be given so that i can calculate tension and hence equate it to mv²/r + mg...

 

[PhanthomJay]

What's missing is the point of release of the pendulum.

 

[Abhishekdas]

Hi...PhanthomJay...

What is the use of the point of release? I thought if i had the tension in the wire somehow my job was done...As i said equate it to mv^2/r + mg...

 

[PhanthomJay]

Yes, and you don't have the tension, so, as you say, the problem is missing information, like is the pendulum released when it's 45 degrees from the negative y axis, or is it 10 degrees, or 5 degrees, etc. ? That is the missing data.

 

[Abhishekdas]

Ya...right...