1. a) A boy pulls a wagon 30m along a sidewalk with a rope tension force of 80N.The force is directed 25° above the horizontal. How much work is done by the boy? b) How much work is done if the same tension force is directed parallel to the ground? 2. A 5kg rabbit and a 12kg Irish setter have the same kinetic energy. If the setter is running at a speed of 4m/sec, how fast is the rabbit running? 3. A large tree can evaporate 500kg of water a day. a. If the water is raised 8m, how much energy must be provided by the tree to lift the water this distance? b. If the evaporation occurs over 12 hr. period, what is the average power in watts needed to provide this increase in gravitational energy?

1. a) A boy pulls a wagon 30m along a sidewalk with a rope tension force of 80N.The force is directed 25° above the horizontal. How much work is done by the boy? b) How much work is done if the same tension force is directed parallel to the ground? 2. A 5kg rabbit and a 12kg Irish setter have the same kinetic energy. If the setter is running at a speed of 4m/sec, how fast is the rabbit running? 3. A large tree can evaporate 500kg of water a day. a. If the water is raised 8m, how much energy must be provided by the tree to lift the water this distance? b. If the evaporation occurs over 12 hr. period, what is the average power in watts needed to provide this increase in gravitational energy?

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter7: Work, Energy, And Energy Resources

Section: Chapter Questions

Problem 7PE: A shopper pushes a grocery cart 20.0 m at constant speed on level ground, against a 35.0 N...

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