COLLEGE PHYSICS,V.1-W/ENH.WEBASSIGN
10th Edition
ISBN: 9781305411906
Author: SERWAY
Publisher: CENGAGE L
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Question
Chapter 8, Problem 14P
(a)
To determine
To show that: The normal force exerted by the second pivot in terms of M, m and g.
(b)
To determine
The women’s position in terms of M, m, L and l.
(c)
To determine
The minimum value of l that will allow the women to reach the end of the beam without it tipping.
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A beam resting on two pivots has a length of 6.00 m and mass 90.0 kg. The pivot under the left end exerts a normal force n1 on the beam, and the second pivot placed a distance 4.00 m from the left end exerts a normal force n2. A woman of mass 55.0 kg steps onto the left end of the beam and begins walking to the right as in Figure P8.22. The goal is to find the woman’s position when the beam begins to tip.
Sketch a free-body diagram, labeling the gravitational and normal forces acting on the beam and placing the woman x meters to the right of the first pivot, which is the origin.
Where is the woman when the normal force n1 is the greatest?
What is n1 when the beam is about to tip?
Use the force equation of equilibrium to find the value of n2 when the beam is about to tip.
Using the result of part (c) and the torque equilibrium equation, with torques computed around the second pivot point, find the woman’s position when the beam is about to tip.
Check the answer to part (e)…
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Chapter 8 Solutions
COLLEGE PHYSICS,V.1-W/ENH.WEBASSIGN
Ch. 8.5 - Using a screwdriver, you try to remove a screw...Ch. 8.5 - A constant net torque is applied to an object....Ch. 8.5 - The two rigid objects shown in Figure 8.21 have...Ch. 8.6 - Two spheres, one hollow and one solid, are...Ch. 8.7 - A horizontal disk with moment of inertia I1...Ch. 8.7 - If global warming continues, its likely that some...Ch. 8 - Math Review The two conditions for equilibrium...Ch. 8 - Math Review Solve the equations 12mv2+12I2=mgh and...Ch. 8 - Prob. 3WUECh. 8 - Physics Review A construction cranes cable lifts a...
Ch. 8 - A man opens a 1.00-m wide door by pushing on it...Ch. 8 - A worker applies a torque to a nut with a wrench...Ch. 8 - Prob. 7WUECh. 8 - A horizontal plank 4.00 m long and having mass...Ch. 8 - A student rides his bicycle at a constant speed of...Ch. 8 - What is- the magnitude of the angular acceleration...Ch. 8 - Prob. 11WUECh. 8 - A bowling ball of mass 7.00 kg is rolling at 3.00...Ch. 8 - A basketball player entertains the crowd by...Ch. 8 - A disk of mass m is spinning freely at 6.00 rad/s...Ch. 8 - Why cant you put your heels firmly against a wall...Ch. 8 - If you see an object rotating, is there...Ch. 8 - (a) Is it possible to calculate the torque acting...Ch. 8 - Why does a long pole help a tightrope walker stay...Ch. 8 - If you toss a textbook into the air, rotating it...Ch. 8 - Stars originate as large bodies of slowly rotating...Ch. 8 - In a tape recorder, the tape is pulled past the...Ch. 8 - (a) Give an example in which the net force acting...Ch. 8 - A cat usually lands on its feet regardless of the...Ch. 8 - A solid disk and a hoop are simultaneously...Ch. 8 - A mouse is initially at rest on a horizontal...Ch. 8 - The cars in a soapbox derby have no engines; they...Ch. 8 - The fishing pole in Figure P8.3 makes an angle of...Ch. 8 - Find the net torque on the wheel in Figure P8.4...Ch. 8 - Figure P8.4 Calculate the net torque (magnitude...Ch. 8 - A dental bracket exerts a horizontal force of 80.0...Ch. 8 - A simple pendulum consists of a small object of...Ch. 8 - Write the necessary equations of equilibrium of...Ch. 8 - Torque and the Two Conditions for Equilibrium 17....Ch. 8 - Prob. 8PCh. 8 - A cook holds a 2.00-kg carton of milk at arm's...Ch. 8 - A meter stick is found to balance at the 49.7-cm...Ch. 8 - Prob. 11PCh. 8 - A beam resting on two pivots has a length of L =...Ch. 8 - Prob. 13PCh. 8 - Prob. 14PCh. 8 - Many of the elements in horizontal-bar exercises...Ch. 8 - Prob. 16PCh. 8 - Prob. 17PCh. 8 - When a person stands on tiptoe (a strenuous...Ch. 8 - A 500.-N uniform rectangular sign 4.00 m wide and...Ch. 8 - A window washer is standing on a scaffold...Ch. 8 - A uniform plank of length 2.00 m and mass 30.0 kg...Ch. 8 - A hungry bear weighing 700. 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Each...Ch. 8 - A car is designed to get its energy from a...Ch. 8 - A horizontal 800.-N merry-go-round of radius 1.50...Ch. 8 - Four objectsa hoop, a solid cylinder, a solid...Ch. 8 - A light rod of length = 1.00 m rotates about an...Ch. 8 - A 240-N sphere 0.20 m in radius rolls without...Ch. 8 - A solid, uniform disk of radius 0.250 m and mass...Ch. 8 - A solid uniform sphere of mass m and radius R...Ch. 8 - The top in Figure P8.55 has a moment of inertia of...Ch. 8 - A constant torque of 25.0 N m is applied to a...Ch. 8 - A 10.0-kg cylinder rolls without slipping on a...Ch. 8 - Use conservation of energy to determine the...Ch. 8 - A giant swing at an amusement park consists of a...Ch. 8 - Each of the following objects has a radius of...Ch. 8 - (a) Calculate the angular momentum of Earth that...Ch. 8 - A 0.005 00-kg bullet traveling horizontally with a...Ch. 8 - A light, rigid rod of length = 1.00 m rotates...Ch. 8 - Haileys comet moves about the Sun in an elliptical...Ch. 8 - A rigid, massless rod has three particles with...Ch. 8 - A 60.0-kg woman stands at the rim of a horizontal...Ch. 8 - A solid, horizontal cylinder of mass 10.0 kg and...Ch. 8 - A student sits on a rotating stool holding two...Ch. 8 - The puck in Figure P8.71 has a mass of 0.120 kg....Ch. 8 - A space station shaped like a giant wheel has a...Ch. 8 - A cylinder with moment of inertia I1 rotates with...Ch. 8 - A particle of mass 0.400 kg is attached to the...Ch. 8 - Additional Problems A typical propeller of a...Ch. 8 - Prob. 68APCh. 8 - Prob. 69APCh. 8 - Prob. 70APCh. 8 - A uniform ladder of length L and weight w is...Ch. 8 - Two astronauts (Fig. P8.80), each haring a mass of...Ch. 8 - S This is a symbolic version of problem 80. 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