Essential University Physics (3rd Edition)
3rd Edition
ISBN: 9780134202709
Author: Richard Wolfson
Publisher: PEARSON
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Chapter 7, Problem 12E
Rework Example 7.1, now taking the zero of potential energy at street level.
EXAMPLE 7.1 Gravitational Potential Energy: Riding the Elevator
A 55-kg engineer leaves her office on the 33rd floor of a skyscraper and takes an elevator up to the 59th floor. Later she descends to street level. If the engineer chooses the zero of potential energy at her office and if the distance from one floor to the next is 3.5 m. what’s the potential energy when the engineer is (a) in her office, (b) on the 59th floor, and (c) at street level?
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Chapter 7 Solutions
Essential University Physics (3rd Edition)
Ch. 7.1 - Suppose it takes the same amount of work to push a...Ch. 7.2 - Gravitational force actually decreases with...Ch. 7.3 - A bowling ball is tied to the end of a long rope...Ch. 7.4 - For which of the following systems is (1)...Ch. 7.5 - A bowling ball is tied to the end of a long rope...Ch. 7.6 - The figure shows the potential energy associated...Ch. 7 - Figure 7.14 shows force vectors at different...Ch. 7 - Is the conservation-of-mechanical-energy principle...Ch. 7 - Why cant we define a potential energy associated...Ch. 7 - Can potential energy be negative? Can kinetic...
Ch. 7 - If the potential energy is zero at a given point,...Ch. 7 - If the difference in potential energy between two...Ch. 7 - If the difference in potential energy between two...Ch. 7 - A tightrope walker follows an essentially...Ch. 7 - If conservation of energy is a law of nature, why...Ch. 7 - Determine the work you would have to do to move a...Ch. 7 - Now lake Fig. 7.15 lo lie in a vertical plane, and...Ch. 7 - Rework Example 7.1, now taking the zero of...Ch. 7 - Find the potential energy associated with a 70-kg...Ch. 7 - You fly from Bostons Logan Airport, at sea level,...Ch. 7 - The potential energy associated with a 60-kg hiker...Ch. 7 - How much energy can be stored in a spring with k =...Ch. 7 - How far would you have to stretch a spring with k...Ch. 7 - A biophysicist grabs the ends of a DNA strand with...Ch. 7 - A skier starts down a frictionless 32 slope. After...Ch. 7 - A 10,000-kg Navy jet lands on an aircraft carrier...Ch. 7 - A 120-g arrow is shot vertically from a bow whose...Ch. 7 - In a railroad yard, a 35,000-kg boxcar moving at...Ch. 7 - You work for a toy company, and youre designing a...Ch. 7 - A 54-kg ice skater pushes off the wall of the...Ch. 7 - Prob. 25ECh. 7 - A particle slides along the frictionless track...Ch. 7 - A particle slides back and forth on a frictionless...Ch. 7 - A particle is trapped in a potential well...Ch. 7 - The reservoir at Northfield Mountain Pumped...Ch. 7 - The force in Fig. 7.14a is given by Fa=FoJ, where...Ch. 7 - A 1.50-kg brick measures 20.0 cm 8.00 cm 5.50...Ch. 7 - A carbon monoxide molecule can be modeled as a...Ch. 7 - A more accurate expression for the force law of...Ch. 7 - For small stretches, the Achilles tendon can be...Ch. 7 - The force exerted by an unusual spring when its...Ch. 7 - The force on a particle is given by F=Al/x2, where...Ch. 7 - A particle moves along the x-axis under the...Ch. 7 - As a highway engineer, youre asked to design a...Ch. 7 - A spring of constant k, compressed a distance x,...Ch. 7 - A child is on a swing whose 3.2-m-long chains make...Ch. 7 - With x x0 = h and a = g, Equation 2.11 gives the...Ch. 7 - The nuchal ligament is a cord-like structure that...Ch. 7 - A 200-g block slides back and forth on a...Ch. 7 - Automotive standards call for bumpers that sustain...Ch. 7 - A block slides on the frictionless loop-the-loop...Ch. 7 - The maximum speed of the pendulum bob in a...Ch. 7 - A mass m is dropped from height h above the top of...Ch. 7 - A particle with total energy 3.5 J is trapped in a...Ch. 7 - (a) Derive an expression for the potential energy...Ch. 7 - In ionic solids such as NaCl (salt), the potential...Ch. 7 - Repeat Exercise 19 for the case when the...Ch. 7 - As an energy-efficiency consultant, youre asked to...Ch. 7 - A spring of constant k = 340 N/m is used to launch...Ch. 7 - A bug slides back and forth in a bowl 15 cm deep,...Ch. 7 - A 190-g block is launched by compressing a spring...Ch. 7 - A block slides down a frictionless incline that...Ch. 7 - An 840-kg roller-coaster car is launched from a...Ch. 7 - A particle slides back and forth in a frictionless...Ch. 7 - A child sleds down a frictionless hill whose...Ch. 7 - A bug lands on top of the frictionless, spherical...Ch. 7 - A particle of mass m is subject to a force...Ch. 7 - A block of weight 4.5 N is launched up a 30...Ch. 7 - Your engineering department is asked to evaluate...Ch. 7 - Your roommate is writing a science fiction novel...Ch. 7 - You have a summer job at your universitys zoology...Ch. 7 - Biomechanical engineers developing artificial...Ch. 7 - Blocks with different masses are pushed against a...Ch. 7 - Nuclear fusion is the process that powers the Sun....Ch. 7 - Nuclear fusion is the process that powers the Sun....Ch. 7 - Nuclear fusion is the process that powers the Sun....Ch. 7 - Nuclear fusion is the process that powers the Sun....
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