Quote (Dontrunaway @ Nov 19 2013 07:30pm)

Ideal Gas Law is chemistry or thermodynamics. Maybe thrown into physics if you aren't in a math-related major.

Quote (Stolem @ Nov 19 2013 02:30pm)

Item #4
Assume all temperature to be exact.

It takes 2.7x10^6 J of heat to bring a quantity of water from 27 C to a boil.

Part A
What is the mass of water?
Express your answer using significant figures.

Q = 2.7x10^6 J
27 C to boiling = 100 C
T = 73 C
(2.7x10^6 J) = m(4186 J/kg)(73 C)
(2.7x10^6 J) = m (4186 J/ kg C)(73 C)
m = ?




Item #5
Assume all temperatures to be exact.
Blood can carry excess heat from the interior to the surface of the body, where the heat is transferred to the outside environment.

If 0.210kg of blood at a temperature of 37.0 ∘C flows to the surface and loses 1800J of heat, what is the temperature of the blood when it flows back into the interior? Assume blood has the same specific heat as water.

0.220 kg blood
37.0 C = T1
loses 1500J
Tf = ?

C~ J/ KG C

-1500 J = (0.220kg)(4186 J / KG C) x (Tf - 236.15)
-1500 J = (920.92 J/ C) x (Tf -37.0 C)
-1500 J / 920.92 J/C = Tf = -37.0 C
-1.63 C = Tf - 37.0 C
-6.63 C + 37.0 C
Tf = 35.37 C

i keep getting wrong answers =((