Question

The coefficient of linear expansion of iron is 1.0 x 10-5 per oC. The surface area of an
iron cube, with an edge length of 5.0 cm, will increase by what amount if it is heated
from 10 oC to 60 oC?

Answer 1

i get 2.5*10^-3 and that is wrong :(

Answer 2

the formula is
ΔL=LαΔT

Answer 3

coefficient of superficial expansion, \(\beta\)=2\(\alpha\)
Now use relation \(\Delta A=A\beta\Delta T\) to find increase in area.

Answer 4

ohhh crap

Answer 5

totally forgot about volume expansion derrr thanks

Answer 6

β=3α by the way

Answer 7

that's not volume expansion. that's area expansion. \(\beta=2\alpha\) and \(\gamma=3\alpha\) we use \(\gamma\) for volumetric expansion.

Answer 8

use \(\beta\) if its expansion for area.

Answer 9

ah k i will just try it..gimme a sec

Answer 10

you asked for a sec, I will give you ten.. :D

Answer 11

ok so i still get the wrong answer...

Answer 12

i did 2*1*10-5*50*5^2=5*10^-3

Answer 13

2*1*10^-5*50*5^2=5*10^-3

Answer 14

(2)*(1*10-5)*(50)*(5^2)=5*10^-3 i think the 5^2 is wrong?

Answer 15

use meter not centimeter for length, and then calculate area.

Answer 16

still wrong

Answer 17

what do you get? i know the answer but yeh

Answer 18

calculate properly, you will get 2.5*10^-6 m^2 . If the answer is in cm^2, just convert it to cm^2

Answer 19

multiply it by 1/2??

Answer 20

lol but thats the wrong answer. it is 0.15cm^2

Answer 21

The question is asking for total area at last and i calculated the difference. so you need to add it to original area. As simple as that.

Answer 22

so total change is 0.00025cm^2 and originally it is 25cm^2 but that doesn't equal 0.15cm^2 if you find the difference

Answer 23

you two asking the same question?
http://openstudy.com/study?login#/updates/4fd21a4ee4b057e7d2211b72

Answer 24

lol yeh looks like it

Answer 25

no i don't have two accounts

Answer 26

and no i don't know that person