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Did you know? One horsepower (1 hp) is the unit of power based on the work that a horse can do in one second. This is defined, in English units, as a

force of 550 lb that can move an object 1 ft in 1 s. In the metric system, 1 hp

equals 745.7 W.

1. Suppose you have an engine that has 750 W of power. How much work does this engine do in 0.55 s?

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2. A race car with a 255 hp engine is able to accelerate from rest to its top speed in 9.00 s. How much work does the car’s engine do in this interval of time?

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3. You have to apply a force of 345 N to push a desk 1.78 m. If you do this in 15.0 s, how much power would you have used?

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4. A ship’s diesel engine has a power output of 13.0x106 W. How much work is done by this engine in 15.0 min?

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5. A Ski-Doo on the other hand, only has a power output of 30 hp. How much work is done by this engine in 15.0 min?

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6. A large SUV has a 355 hp engine. If this SUV travels 13.4 m in 0.9 s, what is the force from the engine?

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7. Two physics students, Will N. Andable and Ben Pumpiniron, are in the weightlifting room. Will lifts the 1000 N barbell over his head 10 times in one minute; Ben lifts the 1000 N barbell over his head 10 times in 10 seconds.

a. Which student does the most work?

b. Which student delivers the most power?

8. A PE student weighs 784 N and is doing push-ups. If he raises his Center of Mass 0.32 meters every push-up that takes one second, how much power has he used to do one push-up?

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9. When doing a chin-up, a physics student lifts her 40-kg body a distance of 0.25 meters in 2 seconds. What is the power delivered by the student's biceps?

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10. A student with a mass of 80.0 kg runs up three flights of stairs in 12.0 sec. The student has gone a vertical distance of 8.0 m. Determine the amount of power used by the student to elevate his body to this height.

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11. Create your OWN power problem to share with your classmates! Write it out as a word problem AND then solve it completely.

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