38. (a) how much work is done lifting a 60 pound chair from the ground to the top of a 20 foot
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Mathematics, 09.10.2019 04:20 ceciliaxo
38. (a) how much work is done lifting a 60 pound chair from the ground to the top of a 20 foot
building with a cable which weighs 1 pound per foot?
(b) how much work is done lifting the same chair from the ground to a height of 5 feet with the same
cable?
39. (a) how much work is done lifting a 10 pound calculus book from the ground to the top of a 30 foot
building with a cable which weighs 2 pounds per foot?
(b) from the ground to a height of 10 feet? (c) from a height of 10 feet to a height of 20 feet?
40. how much work is done lifting an 80 pound injured child to the top of a 20 foot hole using a stretcher
weighing 14 pounds and a cable which weighs 1 pound per foot?
42. how much work is done lifting an 120 pound injured adult to the top of a 30 foot hole using a stretcher
weighing 10 pounds and a cable which weighs 2 pound per foot?
Answers: 1
Mathematics, 21.06.2019 19:30
The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)
Answers: 3
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