Heat is defined to be A. The amount of microscopic
translational and rotational kinetic energy in an object
B. Energy that is transferred to an object because of a temperature difference
C. The temperature of an object in terms of degrees Kelvin.
TmcQ
Energy transferred (Q)
TCQ
200 g of water at 100o is poured into 200 g of water at 0o. The resulting temperature will settle down to be
A. 0o
B. 50o
C. 100o
D. Greater than 50o but less than 100o
E. Less than 50o but more than 0o
cwater=4186 J/kg oC cgold=129 J/kg oC
I use a heating element to put heat into a kg of water and a kg of gold at the same rate. Which changes temperature faster?
A. 1 kg waterB. 1 kg goldC. They both heat up at
the same rate.
TmcQ
Q is energy transferred
Put 100g Al at 100o C into 500g water at 20o C. What is the final T?What will the final T be? 1. 100o
2. 97o
3. 20o
4. 23o
5. 60o
cAl = 900 J/kg oC
cH2O = 4186 J/kg oC
You put 0.4 kg of lead into a bucket containing 1.2 kg of pure acetone. Why in the world did you do that?
Idolatry (Even non-believers find something to believe in)
"As I study ancient scripture, I am more and more convinced that there is significance in the fact that the commandment 'Thou shalt have no other gods before me' is the first of the Ten Commandments." - President Spencer W. Kimball (Aug 1977 Ensign)
It also takes energy to melt a solid or turn a liquid into
gasmLQ
Latent heat of fusion vs. vaporization
You place equal weights of ice (at 0o C) and boiling water (at 100o C) into a well-insulated container. What is the final temperature.A. 0o CB. Between 0o
and 50o CC. 50o CD. Between 50o C
and 100o C mLQ
Lf 3.33x105 J/kgLv 2.26x106 J/kg
c ice 2090 J/kg·oCwater 4186 J/kg·oC steam 2010 J/kg·oC
TmcQ
You place a mass mi at temperature Ti into a mass mw of water at temperature Tw. What will be the final temperature, and how much ice will there be?
You place equal weights of ice (at -20o C) and water (at 0o C) into a well-insulated container. How much boiling water must be added to produce only water at 0o C.
Lf 3.33x105 J/kgLv 2.26x106 J/kg
c ice 2090 J/kg·oCwater 4186 J/kg·oC steam 2010 J/kg·oC
