QUESTION 3 What is the total mechanical energy of an object that has a potential energy of 65 J and kinetic energy of 20 J? O A. 20J O B. 40) OC. 65) O D.851 QUESTION 4 What is the mass of an object if its gravitational potential energy at 15m above the ground is 735 J? O A. 20kg O B. 10kg OC. skg O D.15kg

QUESTION 3 What is the total mechanical energy of an object that has a potential energy of 65 J and kinetic energy of 20 J? O A. 20J O B. 40) OC. 65) O D.851 QUESTION 4 What is the mass of an object if its gravitational potential energy at 15m above the ground is 735 J? O A. 20kg O B. 10kg OC. skg O D.15kg

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter8: Conservation Of Energy

Section: Chapter Questions

Problem 8.10CQ: In Chapter 7, the work-kinetic energy theorem, W = K, was introduced. This equation states that work...

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In Chapter 7, the work-kinetic energy theorem, W = K, was introduced. This equation states that work done on a system appears as a change in kinetic energy. It is a special-case equation, valid if there are no changes in any other type of energy such as potential or internal. Give two or three examples in which work is done on a system but the change in energy of the system is not a change in kinetic energy.
(a) Calculate the work done on a 1500-kg elevator car by its cable to lift it 40.0 m at constant speed, assuming friction averages 100 N. (b) What is the work done on the lift by the gravitational force in this process? (c) What is the total work done on the lift?
In 1990, Walter Arfeuille of Belgium lifted a 281.5-kg object through a distance of 17.1 cm using only his teeth. (a) How much work was done on the object by Arfeuille in this lift, assuming the object was lifted at constant speed? (b) What total force was exerted on Arfeuilles teeth during the lift?
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(a) Can the kinetic energy of a system be negative? (b) Can the gravitational potential energy of a system be negative? Explain.
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