Question

28. Wires of the same length are made from metals A and B. Metal A ha a coefficient of linear expansion equal to twice that of metal B. Both wires are heated independently, but uniformly from an initial temperature of 40 degrees celcius and the heating is stopped when their final lengths are again equal. If wire A is removed from the heat source when its final temperature is 50 degrees celcius, what is the final temperature of wire B?

I'm so confused about this one, but I know it's with this formula: ΔL = αLΔT

30. A hydrogen molecule of molecular weight 2 has the same kinetic energy as an unknown molecule of molecular weight 20. What is the ratio of the velocity of the hydrogen molecule to the velocity of the unknown molecule?

So I know KE = 1/2 mv², but I'm still confused. help, thanks!

Answer 1