# Exam 4 - Exam 4 Physics PointsAwarded PointsMissed...

This preview shows pages 1–3. Sign up to view the full content.

Exam 4 Physics Points Awarded 44.00 Points Missed 6.00 Percentage 88.0% . . . 1 An aluminum tank of volume 0 0300 m3 is filled to the top with mercury at 20 0 . . . The tank is placed inside a chamber with an interior temperature of 70 0 ℃ . - The coefficient of volume expansion for mercury is 1 82 x 10 4 / ℃ and the . - / . coefficient of linear expansion of aluminum is 23 0 x 10 6 ℃ After the tank and , its contents reach thermal equilibrium with the interior of the chamber how much [ . - . .] mercury has spilled? Note 3 5 x 10 2 m2 is 0 0035 square meters . a . - 2 52 x 10 5 m3 . b . - 2 00 x 10 4 m3 . c . - 1 92 x 10 4 m3 . d . - 6 60 x 10 5 m3 . e . - 1 69 x 10 4 m3 Question Details: An aluminum tank of volume 0.0300 meters cubed is filled to the top with mercury at 20 degrees C. THe tank is placed inside a chamber with an interior temperature of 70.0 degrees C. The coefficient of volume expansion for mercury is 1.82 x 10-4/C; and the coefficient of linear expansion of aluminum is 23.0 x 10-6/C. After the tank and its contents reach thermal equilibrium with the interior of the chamber, how much mercury has spilled [Note 3.5 X 10-3 m2 is 0.0035 square meters] Response Details: change in volume of Hg = ΔV = Vγ(ΔT) = .03*.000182*50 = .000273 m^3 change in length of tank = ΔL = Lα(ΔT) change in width of tank = ΔW = Wα(ΔT) change in height of tank = ΔH = Hα(ΔT) change in volume of tank = (L+ΔL)(W+ΔW)(H+ΔH) - LWH ˜ LWH + LWΔH + LHΔW + WHΔL - LWH (neglecting higher order terms like ΔLΔW, etc., since they are very small) = LWΔH + LHΔW + WHΔL = LWH (3αΔT) = 3αVΔT = 3*.000023*.03*50 = .0001035 m^3 Hg spilled = .000273 m^3 - .0001035 m^3 = .0001695 m^3 . 2 . . A household humidifier continuously takes water in at 20 0 ℃ at a rate of 5 60 x - / 10 5 kg s . and heats it until it evaporates . / , If the cost of electricity is \$0 14 kWh [ : = . what is the daily cost of operating the humidifier? Notes one kWh 3 60 x 10^6 ; , / ( ); J and for water the specific heat capacity is 4186 J kg ∙℃ the latent heats of . / . / , . fusion and vaporization are 3 35 x 10^5 J kg and 2 26 x 10^6 J kg respectively . a . \$0 65 . b . \$0 49 . c . \$0 31 . d . \$0 58 . e . \$0 70 TUTORVISTA

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
: Textbook page 370 example 10 = Q cm∆T A household humidifier continuously takes water in at 20.0 °C at a rate of 5.60 × 10–5 kg/s and heats it until it evaporates. If the cost of electricity is \$ 0.14/kWh, what is the daily cost of operating the humidifier? Notes: one kWh = 3.60 × 106 J; and for water, the specific heat capacity is 4186 J/(kg • °C) the latent heats of fusion and vaporization are 3.35 × 105 J/kg and 2.26 × 106 J/kg, respectively. Best Answer - Chosen by Voters
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 07/24/2010 for the course PHYSICS ph205 taught by Professor Brumm during the Spring '10 term at Grantham.

### Page1 / 8

Exam 4 - Exam 4 Physics PointsAwarded PointsMissed...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online