Name:
Date:
Gavilan College AMT 100
Physics
Worksheet #3 – Work & Power
Points: 11
1 gallon of avgas = 113,280 BTU (British Thermal Unit).
1 BTU = 778 ft-lb.
1 HP (horsepower) = 33,000 ft-lb/minute = 550 ft-lb/sec.
1 HP = 746 watts.
Show all your work!
1. How much work is exerted when lifting 150 lbs 250 feet (in ft-lbs)?
2. How much work is exerted when you lift 5 boxes, each weighing 17 lbs, 23 feet (in ft-lbs)?
3. How much work can be done by a gallon of avgas (in ft-lbs)?
4. 5500 ft-lbs of work would lift a 250 lb weight how high?
5. An engine is 28% efficient. If 600 ft-lbs of energy is put into the engine, how much work will
come out (in ft-lbs)?
6. An engine is 25% efficient. If the engine burns 5 gallons of avgas, how much work will the
engine put out (in ft-lbs)?
7. 45 HP equals how many watts?
8. How much horsepower is needed to raise 6,500 lbs 3,500 ft in 3 minutes?
9. How much horsepower is needed to raise 7 tons (2,000 lbs/ton) 175 ft in 25 seconds?
10. An engine is 28% efficient. It burns 18 gallons of avgas per hour. How much power does the
engine put out?
11. Using the information from question 10, how much power is wasted?
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