Physics 140 Homework 1. Assigned 1/31/2022 Due 2/14/2022
Problems/Ques ons
Units, Energy, Power
1. The United States (US) consumes 10 20 J (joules) of energy each year. What is the average power
consump on of the US in TW (terawa s)?
2. How many TWh (terawa -hours) of energy does the US use in one year?
3. How much average power per person does the US consume? You can take the current US popula on
to be 300 million.
4. Look up the IEA graph on “ World total energy supply by geographical region”. On the Physics 140
Canvas page go Pages —> Link —> IEA World Energy Sta s cs
a) If you hover over the graph with your mouse you can get the total energy usage for the
Americas, Europe, Asia, Africa, and Oceania. What is the total energy use per person in each of these
areas in 2018? You will need to nd out the popula on of these areas.
b) Since 1990, Asia has increased total energy use the most. Speculate as to the reason why.
Blackbody radia on
5. Go to the PHET Web demo of blackbody radia on (Canvas —> Pages —> Links —> PHET Web Demo
on Blackbody Radia on
(direct link) h ps://phet.colorado.edu/en/simula ons/blackbody-spectrum
Note that as you slide the temperature scale up and down, you will have to adjust the X and Y axes of
the graph with the +/- bu ons.
5a. What is the peak wavelength emi ed by an oven set at 350 degrees F?
5b. What is the peak wavelength emi ed by Venus?
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5c. What is the peak wavelength emi ed by a living human body?