A stay-at-home mom watches soap operas for 1.5 h each day and her husband vegges out in front of the tube for around 2 h a night
He also watches the football games on Saturday and Sunday during football season (two games each day, 6 hours of watching). How much does this family pay to watch TV every year? Assume the cost of electricity is $0.08/kWh.
We assume from the description that this is the weekday ritual—watching the TV
for a total time of 3.5 h. From Table 8.7, we use 200 W as the power drawn by the TV. So,
we find 5 d x 3.5 h/d x 200 W = 3500 Wh = 3.5 kWh. Weekend watching totals 12 h, so
energy use from the weekend totals 200 W x 12 h = 2400 Wh = 2.4 kWh. Total weekly
energy use is 5.9 kWh. The cost is 5.9 kWh x $0.08/kWh = $0.47.
You might also like to view...
If the momentum of an object is doubled, its speed must have increased by
A. 4 B. 2 C. 0.5 D. 0.25
The "horns" of the crescent moon point
a. always away from the Sun. b. in random directions. c. down toward Earth. d. always away from Earth.
Where are the Cepheid and RR Lyrae variable stars located on the H-R Diagram?
a. just above and to the right of B type stars b. just above and to the right of O type stars c. in the variable strip d. in the instability strip e. outside the H-R Diagram as missing items
Intensity: A sinusoidal electromagnetic wave has a peak electric field of 8.00 kV/m. What is the intensity of the wave? (c = 3.0 × 108 m/s, ?0 = 4? × 10-7 T ? m/A, ?0 = 8.85 × 10-12 C2/N ? m2)
A. 170 kW/m2 B. 85 kW/m2 C. 21 kW/m2 D. 11 kW/m2