a) A block of silver, mass m s = 1.79 kg, is heated in a furnace to temperature
ID: 2217852 • Letter: A
Question
a) A block of silver, mass ms = 1.79 kg, is heated in a furnace to temperature Ts, but remains solid. It is now dropped on a block of ice, mass mi = 425 g and temperature Ti = 0o C. The combination reaches equilibrium at temperature Tf = 24.3 o C. Find Ts, the initial temperature of the silver.
??C
b)A microwave oven produces energy at a rate of P = 1185 W, all in the form of microwaves. When a cup of water is placed into this oven, 65.3% of the microwaves are absorbed by the water. If a cup containing mw = 174 grams of water (227 g equals 8 ounces) starts at temperature Tw = 20.8o C: find t, the time it will take the water to reach its boiling point.
4 ??s
Explanation / Answer
a) heat given by silver mass = heat taken by ice 1.79*.24*(Ts-24.3) = .425*(334+4.18*24.3) Ts = 455.2 deg C b) power emitted by microwave*eff*time = heat adsorbed by water 1185*t*.653 = .174*4.18*(100-20.8)*1000 t= 74.44 seconds
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.