A 4.00 x 10^2-g glass coffee cup is at room temperature, 20.0ºC. It is then plunged into hot dishwater, 80.0ºC. If the temperature of the cup reaches that of the dishwater, how much heat does the cup absorb? Assume the mass of the dishwater is large enough so its temperature doesn't change appreciably.
2007-01-19 17:19:15 · 3 answers · asked by smiyololo 1 in Science & Mathematics ➔ Physics
heat absorb, Q = mcT, where T is change in temperature, c is heat capacity of water.
Q = 4.00 x 10^2 x 10^-3 x 4200 x (80 - 20)
= 100800 J
2007-01-19 18:23:14 · answer #1 · answered by li mei 3 · 0⤊ 0⤋
just find the heat capacity of glass. this is the amount of energy it takes to heat one kg of glass by one degree. then multiply by the temperature rise (60 C) and the mass of the glass to find the energy in Joules.
heat capacity - 0.84 kJ/kgK
mass - 4x10^2 g = 0.4 kg
temp. rise - 60 K
energy = 0.84 x 0.4 x 60 = 20.16 kJ
2007-01-19 17:32:17 · answer #2 · answered by Critical Mass 4 · 0⤊ 0⤋
the result comes from the formula
Q = m c (t(final)-t(initial)
here m = 400g , c=1 , t(final)-t(initial) = 80-20 =60
so RESULT Q = 60*1*400 = 24000 cal= 24000*4.18=100320 J
2007-01-19 18:03:06 · answer #3 · answered by maussy 7 · 0⤊ 0⤋