# Young's modulus question .

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.

## 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
Homework Helper
Gold Member

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

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
Homework Helper
Gold Member

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.

Ya....right....