Calculating Temperature Increase From Hand Rubbing Work

[narutoish]

Homework Statement

Rubbing your hands together warms them by converting work into thermal energy. If a woman rubs her hands back and forth for a total of 10 rubs a distance of 7.50 cm each and with a frictional force averaging 45.0 N, what is the temperature increase? The mass of tissue warmed is only 0.100 kg, mostly in the palms and fingers.

Homework Equations

work = force * distance

The Attempt at a Solution

i can find the work, but after that I don't know how to connect that to temperature change.

 

[lendav_rott]

Some of the work is converted to heat, I would go with Q = cmΔT , but I have no idea what c is for human skin, tissue, cells or whatever. If you assume the process is 100% efficient, all the work done goes toward heating the skin, then all you would need is the c , the amount of energy it takes to heat up 1 kg of mass by 1 K
It is said lots of it in our body is water, the c for water is 4.2 kJ/ kgK, the surface of the skin is sweat so water again, but I'm not a beauty salon worker :/, can't help you any further at the moment.

 

[adjacent]

Hi Naruto,
Specific heat capacity of human body on average is 3470 J/(kg⋅°C).So I think you should use that.

 

[narutoish]

so does all the work convert to heat?

 

[lendav_rott]

Never does. There is no further data on the assignment, therefore I can assume the process is 100% efficient.

 

[narutoish]

Thanks guys I got it.