Science Buddies: "Ask an Expert"

So, I come across this question I'm not sure and I'm a beginner for Physics. The question goes like this: A 0.25 kg steel ball at 80°C is placed on a large block of ice. Calculate the mass of ice melted by the heat from the steel ball.
[Specific heat capacity of steel, c= 420Jkg-1°C-1 , Specific latent heat of fusion l =3.36x10to the power of 5 Jkg-1]

Please, help me to understand the concept. Thank you!

Good question. I looked online for some useful information and I will say that it probably made things less clear rather than more. Knowing about heat capacity was one of the driving forces behind the development of Quantum Mechanics. Therefore your question is far from trivial. But, the work to find out the critical numbers has been done for us.

Here’s how I look at the problem. Since you didn't give the mass of the block of ice I assume that its mass is large enough to absorb all of the heat from the steel ball without completely melting. The problem can be then broken down into two parts.

1) How much heat will the steel ball give up while its temperature changes from 80 C to 0 C (given all the heat goes into the ice and none into the surrounding air)?

2) How much ice will be melted by that amount of heat?

Roughly speaking, the change in Heat (ball) = (T1 - T2) [in degrees Kelvin or C depending on units] times the specific heat capacity of the ball.

The amount of ice melted is ΔH times the heat of fusion of ice at 273K (0 C). The temperature of the ice will remain constant as long as the block has not completely melted.

I hope this makes it clearer what the problem is asking and a suggested procedure. The details I leave to you. You may have to maneuver the degrees C and K a bit.

If it’s still not clear let me know what isn’t.

Colin

Thanks for the explanation! I'm glad I'm able to understand on what you are explaining~

Colin gave you some great and in-depth information to help solve the problem. Please keep in mind, however, that the Ask an Expert forums are not for help with homework. Experts are available to offer help with science fair projects. Homework questions that require independent research or synthesis of assigned class reading, etc., are outside of the scope of these forums.

Science Buddies Staff