The cable of a crane is lifting a 750 kgkg girder. The girder increases its speed from 0.25 m/sm/s to 1.25 m/sm/s in a distance of 3.3 mm. this is not a graded assignment it's just a practice problem i have only one more try on How much work is done by tension? Express your answer with the appropriate units. View Available Hint(s)for Part B Hint 1for Part B. How to approach the problem The tension and gravity do work. Kinetic energy of the system changes. Use the energy principle to find the work done by tension. DO NOT SAY THE ANSWER IS 500 or something I tried that and that's the wrong answer, ot should be the process i will show below but with my numbers, I wanted to make sure to be right cause I have one try left only, example question that is the same but with different number, I don't know if this is right for sure but looks kinda right at least right track for the process The cable of a crane is lifting a 750 kg girder. The girder increases its speed from 0.25 m/s to 0.75 m/s in a distance of 3.5 m. a. How much work is done by gravity? b. How much work is done by tension (a) The amount of work done by gravity on the crane is 25,725 J. (b) The amount of work done by tension is 25,912.5 J. Work done by gravity The amount of work done by gravity on the crane is calculated as follows; W = mgh W = 750 x 9.8 x 3.5 W = 25,725 J Work done by tension The amount of work done by tension is calculated from conservation of mechanical energy as follows; W = ΔK.E + ΔP.E W = ¹/₂m(v² - u²) + mg(hf - hi) W = ¹/₂ x 750 x (0.75² - 0.25²) + 750 x 9.8 x (3.5 - 0) W = 187.5 + 25,725 W = 25,912.5 J

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 38PE: (a) How long will it take an 850-kg car with a useful power output of 40.0 hp (1hp=746W) to reach a...

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Hint 1for Part B. How to approach the problem

The tension and gravity do work. Kinetic energy of the system changes. Use the energy principle to find the work done by tension. DO NOT SAY THE ANSWER IS 500 or something I tried that and that's the wrong answer, ot should be the process i will show below but with my numbers, I wanted to make sure to be right cause I have one try left only,

example question that is the same but with different number, I don't know if this is right for sure but looks kinda right at least right track for the process

The cable of a crane is lifting a 750 kg girder. The girder increases its speed from 0.25 m/s to 0.75 m/s in a distance of 3.5 m. a. How much work is done by gravity? b. How much work is done by tension

(a) The amount of work done by gravity on the crane is 25,725 J.

(b) The amount of work done by tension is 25,912.5 J.