ProblemSet08-3

# ProblemSet08-3 - (a)Find the number of bulbs they have to...

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Physics 204A Problem Set #8-3 1. A top fuel dragster has a mass of 1000kg and it can accelerate from zero to 100mph (44.0m/s) in 0.840s. Find (a)the minimum amount of work that must be done by the engine and (b)the minimum average power output of the engine. 2. Pick four appliances you own from the list below. For each one estimate the number of hours you run it each month. Calculate the total energy you use in kWh and estimate the cost at about 12¢ per kWh. Express your answer in a table. Appliance Power (W) Time (h) Energy (kWh) Cost (\$) 3. Power companies subsidize the price of compact fluorescent bulbs to save on building power plants. A 300MW plant costs about \$1 billion. Assume that each compact fluorescent replaces a 60.0W bulb with a 13.0W bulb that puts out the same amount of light.
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Unformatted text preview: (a)Find the number of bulbs they have to replace to avoid having to build a 300MW plant. (b)Assume they subsidize each bulb by \$10, find the total cost of the subsidy. (c)Compare the cost of the subsidy on the bulbs to the cost of a new power plant. 4. An airplane traveling at 650km/h for 4.00hr has engines that exert an average thrust of 14.0kN to maintain this constant speed. Find (a)the power provided by the engine and (b)the total work done by the engine. Appliance Power (W) Blender 500 Clock Radio 5 Coffee Maker 1,700 Computer - PC 300 Electric Blanket 400 Electric Curlers 300 Frying Pan 1,250 Hair Dryer 1,875 Iron 1,200 Light Bulbs 60 Microwave 1,700 Washing Machine 2,200 Water Heater 4,000 TV - Color 300 Freezer 2,100 Garage Door Opener 1,000 House Heater 725...
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