# Need help with this question.

• naim

## Homework Statement

i came across this question while revising, can someone talk me through it please. I need to calculate the dimensional change.

The stator of an electric motor winding is to be expansion fitted into its housing. if the diameter of the stator at 20 degrees C is 150.1 mm and the diameter of the housing is at 20 degrees C is 150 mm, determine the temperature to which the housing must be raised to facilitate the assemble.

The coefficient is 12x10 ^-6 degrees

## Homework Equations

∆L/L = α∆T, α is linear thermal expansion coef

## The Attempt at a Solution

You are given L, α and ∆L is something you can calculate (how much stretching do you need?). Then use that equation to solve for ∆T.

do you mind showing me how to do it ? with a different question perhaps? i have just started to learn and I am not very good at maths

Hi naim! http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

You provided this equation: ∆L/L = α∆T, α is linear thermal expansion coef
and you said The coefficient is 12x10 ^-6 degrees

I think the coefficient of linear expansion should be expressed "per degree", i.e., 12x10 ^-6 /degree
and you should have been told whether Celcius or Farenheit

So the first step into fill in the information you know:
L =
∆L =
α =
∆T =

If necessary, convert the above to standard units because equations always require that the data be expressed in standard units.

Next, re-arrange the equation so the unknown quantity is on one side by itself.

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Thanks dude :)

can someone help me with this ?

Dry steam is compressed isothermally from a pressure of 1 bar to 4 bar. if the initial volume is 0.5 m^3, calculate the volume of the steam after compression