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A mobile is formed by supporting four metal butterflies of equal mass m from a string of length L. The points of support are evenly spaced a distance ℓ apart as shown in Figure P5.54. The string forms an angle θ1 with the ceiling at each endpoint. The center section of string is horizontal. (a) Find the tension in each section of string in terms of θ1, m, and g. (b) In terms of θ1, find the angle θ2 that the sections of string between the outside butterflies and the inside butterflies form with the horizontal. (c) Show that the distance D between the endpoints of the string is
Figure P5.54
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Chapter 5 Solutions
Bundle: Physics for Scientists and Engineers with Modern Physics, Loose-leaf Version, 10th + WebAssign Printed Access Card for Serway/Jewett's Physics for Scientists and Engineers, 10th, Multi-Term
- A makeshift sign hangs by a wire that is extended over an ideal pulley and is wrapped around a large potted plant on the roof as shown in Figure P6.10. When first set up by the shopkeeper on a sunny and dry day, the sign and the pot are in equilibrium. Is it possible that the sign falls to the ground during a rainstorm while still remaining connected to the pot? What would have to be true for that to be possible? FIGURE P6.10 Problems 10 and 11.arrow_forwardRoss and Rachel are fighting if they were on a break. Ross is trying to get his stuff weighing 150. N placed on an inclined plane by pulling it upwards parallel to the inclined plane with 150. N force. However, Rachel is trying to stop Ross by exerting 50.0 N perpendicular to the inclined plane. The coefficients of friction between the box and the incline are us = 0.450 and uk = 0.350. Rachel was able to stop Ross. The object is in static equilibrium. Rachel wins. The object is impending to move up. Nobody wins; the object slides down to the plane. Ross was able to get the object. The object slides up along the incline. 50 N F·R·I·E·N·D·S 30° Was Ross able to get the object or was Rachel able to stop him? (Ctrl)- 150 Narrow_forwardA mule is harnessed to a sled having a mass of 201 kg, including supplies. The mule must exert a force exceeding 1270 N at an angle of 30.3° (above the horizontal) in order to get the sled moving. Treat the sled as a point as a particle. a) Calculate the normal force (in N) on the sled when the magnitude of the applied force is 1270 N. (Enter the magnitude.) N (b) Find the coefficient of static friction between the sled and the ground beneath it. (c) Find the static friction force (in N) when the mule is exerting a force of 6.35 ✕ 102 N on the sled at the same angle. (Enter the magnitude.) Narrow_forward
- Consider a 25-kg block on a frictionless inclined plane held in place by a steel cable as shown in the figure. The cable is parallel to the surface of the incline. What is the magnitude of the tension on the steel cable? 25 kg 30° 212 N O 245 N O none of the choices O 123 N O 458 Narrow_forwardAnswer must be according the correct signifcant numbers.arrow_forwardYou are a bully. You pin a 48 kg dweeb to a wall so that his feet aren't touching the ground. Your arm is extended so that it makes an angle 28 degrees with the horizontal. The dweeb's back is so sweaty with fear that there is no friction between his back and the wall. What is the magnitude of the force , in N, you must apply to keep the dweeb in equilibrium? (Use g = 10 m/s2) This scenario is represented schematically below. Unfortunately for you, years later the dweeb is your boss and he makes your life miserable. (Please answer to the fourth decimal place - i.e 12.3445)arrow_forward
- A heavy sled is being pulled by two people, as shown in the figure. The coefficient of static friction between the sled and the ground is , = 0.579, and the kinetic friction coefficient is = 0.419. The combined mass of the sled and its load is m = 351 kg. The ropes are separated by an angle = 21.0. and they make an angle 0 = 30.1° with the horizontal, Assuming both ropes pull equally hard, what is the minimum rope tension required to get the sled moving? 1214.39 minimum rope tension: incorrect If this rope tension is maintained after the sled starts moving, what is the sled's acceleration? 1.56 acceleration: Attempt 1 N m/s?arrow_forwardm F 0 You are pressing a box against a sloped ceiling, perpendicular to the ceiling itself, as shown in the figure. The mass of the box is m=3.3 kg, the angle of the ceiling is 0=37°, and the coefficients of friction are μs-0.31 and μk=0.2. (a) What is the minimum force needed from you to keep the box at rest? N (b) Choosing up the sloping ceiling to be the positive direction, suppose you push with a force 4 N smaller than your answer to the previous part. What will be the acceleration of the box? m/s²arrow_forwardA block of mass 20kg is pushed against a vertical wall by force P. The coefficient of friction between the surface and the block is 0.2. If theta = 30 degrees, what is the minimum magnitude of P to hold the block still?I understand that in order for the block to sit motionless, the net forces acting on the block must be zero. I set my equation to be Net Force = 0 = Psin(theta) + Force Friction - Force Gravity.Which I rearranged as P = (Force Gravity - Force Friction)/sin(theta) or P = (mg-μ(mg))/sin(theta)Doing this gives me a value of 313.6N rather than 202.9N which I should be getting. What am I doing wrong?arrow_forward
- A roofer is shingling a roof having a slope of 30.0°. The roofer is pulling a bundle of shingles, X, up the roof with a rope. Another rope connects bundle X to bundle Y farther down the roof, as shown. Each bundle has a mass of 18.0 kg. The coefficient of static friction is 0.550 . What force must the roofer exert to start the shingles moving up the roof?arrow_forwardYou are pushing a metal crate against a metal floor. The two surfaces have a static coefficient of friction of 0.62 and a kinetic coefficient of friction of 0.50. The floor is horizontal, and the crate has a mass of 25.0 kg. What is the minimum force you need to apply to get the crate moving from rest? Give your answer in units of N, to three significant figures.arrow_forwardPahelp po with solution po.arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning