Homework Help: Force of an Expanding Ingot

1. Jul 15, 2017

AutumnBeds

1. The problem statement, all variables and given/known data

(c) A standard aluminium ingot is 746 mm in length at 20°C. When the ingots reach a temperature of 500°C. Calculate:

(ii) the induced force in an ingot assuming it has become jammed in the furnace and is NOT free to expand
y = Modulus of elasticity for aluminium: 69 GPa
A=0.019m^2
Change in length= 7.95mm
Original Length=740mm

2. Relevant equations

F=Ay(change in length / original length)

3. The attempt at a solution

F=0.019*69x10^9(7.95/740)
F=14084391 newtons

I've been to solve the above and have been told my original answer was incorrect. I've relooked at my work and come up with the above.

Any helps as to whether this looks correct would be greatly appreciated.

Thanks

2. Jul 15, 2017

haruspex

I assume you correctly calculated the increase in length due to temperature and got 7.95mm.
How did 746mm turn into 740mm? Is that a typo?
You quote too many significant figures for the given data.
Other than that, your work looks right.

3. Jul 15, 2017

AutumnBeds

Yeah that looks like a typo. The increase in length has been confirmed correct as part of another question.

Thanks for the confirmation.