Greatest elongation and escape velocity HELP

[itheo92]

Homework Statement

Three wires are made of same materials. Which wire will have the greatest elongation?
wire1: length: 50cm, diameter: 0.5mm
wire2: length: 100cm, diameter: 1mm
wire3: length: 300cm, diameter: 3mm

Homework Equations

The Attempt at a Solution

I know, the wire having greatest elongation will have the greatest Young's modulus.
So, i have to calculate the young modulus from the given data of the three wires. but I can't get a equation to put.
actually I'm weak at the elasticity related issues, but I guess It's not too hard...

Homework Statement

The escape velocity from Earth is v. if the body is projected from the Earth in a direction of 45 degree to the vertical then it's escape velocity is??

Homework Equations

The Attempt at a Solution

I think, the escape velocity will not change...it's same for all direction...am I wrong?

 

[PhanthomJay]

I would like to welcome you to these forums and would ask that you post separate unrelated questions in separate posts, and to please show an attempt at your work when posting, listing relevant equations.

Homework Statement

Three wires are made of same materials. Which wire will have the greatest elongation?
wire1: length: 50cm, diameter: 0.5mm
wire2: length: 100cm, diameter: 1mm
wire3: length: 300cm, diameter: 3mm

Homework Equations

The Attempt at a Solution

I know, the wire having greatest elongation will have the greatest Young's modulus.

this is not true

So, i have to calculate the young modulus from the given data of the three wires. but I can't get a equation to put.

It is given that all wires have the same material, therefore, they all have the same Young modulus, which is a property of the material structure.

actually I'm weak at the elasticity related issues, but I guess It's not too hard...

You'll need to list the relevant equation that relates elongation to Young's modulus and the given variables.

Homework Statement

The escape velocity from Earth is v. if the body is projected from the Earth in a direction of 45 degree to the vertical then it's escape velocity is??

Homework Equations

The Attempt at a Solution

I think, the escape velocity will not change...it's same for all direction...am I wrong?

You may very well be right, with the usual assumptions of no air resistance, etc., but why do you say that?