Problem A moving electron has a Kinetic Energy Kg. After a net amount of work is done on it, the electron is moving one-quarter as fast in the opposite direction. What is the work done W in terms of K4? Solution To solve for the work done, first we must determine what is the final kinetic energy of the electron. By concept, we know that K1=(1/2)mv², K2=(1/2)mv2 But it was mentioned that: v2=( so, Kz in terms of v, is K2=( )mv², Substituting the expression for K1 results to

Problem A moving electron has a Kinetic Energy Kg. After a net amount of work is done on it, the electron is moving one-quarter as fast in the opposite direction. What is the work done W in terms of K4? Solution To solve for the work done, first we must determine what is the final kinetic energy of the electron. By concept, we know that K1=(1/2)mv², K2=(1/2)mv2 But it was mentioned that: v2=( so, Kz in terms of v, is K2=( )mv², Substituting the expression for K1 results to

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter6: Energy Of A System

Section: Chapter Questions

Problem 44P

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Integrated Concepts (a) What force must be supplied by an elevator cable to produce an acceleration of 0.800 m/s2 against a 200-N frictional force, if the mass of the loaded elevator is 1500 kg? (b) How much work is done by the cable in lifting the elevator 20.0 m? (c) What is the final speed of the elevator if it starts from rest? (d) How much work went into thermal energy?
A student has the idea that the total work done on an object is equal to its final kinetic energy. Is this idea true always, sometimes, or never? Ii it is sometimes true, under what circumstances? If it is always or never true, explain why.
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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 did Arfeuille do on the object? (b) What magnitude force did he exert on the object during the lift, assuming the force was constant?
. The fastest that a human has run is about 12 m/s. (a) If a pole vaulter could run this fast and convert all of her kinetic energy into gravitational potential energy, how high would she go? (b) Compare this height with the world record in the pole vault.
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