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Select the correct answer
A washing machine uses 1.8 x 105 watts of power. If it is in use for 2 hours per day (on average), how many kilowatt hours will it use in 30 days?
A
1.1 x 104 kilowatt hours
B. 36 kilowatt hours
C. 18 kilowatt hours
D. 540 kilowatt hours
E.
1.1 x 106 kilowatt hours

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system

Which of the following forces require physical contact? tension air resistance friction magnetic force applied force