Concept explainers
CP A 1.80-m-long uniform bar that weighs 638 N is suspended in a horizontal position by two vertical wires that are attached to the ceiling. One wire is aluminum and the other is copper. The aluminum wire is attached to the left-hand end of the bar, and the copper wire is attached 0.40 m to the left of the right-hand end. Each wire has length 0.600 in and a circular cross section with radius 0.280 mm. What is the fundamental frequency of transverse standing waves for each wire?
Want to see the full answer?
Check out a sample textbook solutionChapter 15 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
The Cosmic Perspective Fundamentals (2nd Edition)
University Physics (14th Edition)
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Conceptual Physics (12th Edition)
Physics (5th Edition)
Applied Physics (11th Edition)
- A copper rod with length 1.4 m and cross-sectional area 2.0 cm2 is fastened to a steel rod of length L and cross-sectional area 1.0 cm2. The compound structure is pulled on each side by two forces of equal magnitude 6.00 104 N (Fig. P14.57). Find the length L of the steel rod if the elongations (L) of the two rods are equal. Use the values Ysteel = 2.0 1011 Pa and YCu = 1.1 1011 Pa. FIGURE P14.57arrow_forwardA uniform rod of weight Fg and length L is supported at its ends by a frictionless trough as shown in Figure P12.49. (a) Show that the center of gravity of the rod must be vertically over point O when the rod is in equilibrium. (b) Determine the equilibrium value of the angle . (c) Is the equilibrium of the rod stable or unstable? Figure P12.49arrow_forwardWhy is the following situation impossible? A worker in a factory pulls a cabinet across the floor using a rope as shown in Figure P12.36a. The rope make an angle = 37.0 with the floor and is tied h1 = 10.0 cm from the bottom of the cabinet. The uniform rectangular cabinet has height = 100 cm and width w = 60.0 cm, and it weighs 400 N. The cabinet slides with constant speed when a force F = 300 N is applied through the rope. The worker tires of walking backward. He fastens the rope to a point on the cabinet h2 = 65.0 cm off the floor and lays the rope over his shoulder so that he can walk forward and pull as shown in Figure P12.36b. In this way, the rope again makes an angle of = 37.0 with the horizontal and again has a tension of 300 N. Using this technique, the worker is able to slide the cabinet over a long distance on the floor without tiring. Figure P12.36 Problems 36 and 44.arrow_forward
- A horizontal, rigid bar of negligible weight is fixed against a vertical wall at one end and supported by a vertical string at the other end. The bar has a length of 50.0 cm and is used to support a hanging block of weight 400.0 N from a point 30.0 cm from the wall as shown in Figure P14.81. The string is made from a material with a tensile strength of 1.2 108 N/m2. Determine the largest diameter of the string for which it would still break. FIGURE P14.81arrow_forwardWhen a person stands on tiptoe on one foot (a strenuous position), the position of the foot is as shown in Figure P12.32a. The total gravitational force Fg on the body is supported by the normal force n exerted by the floor on the toes of one foot. A mechanical model of the situation is shown in Figure P12.32b, where T is the force exerted on the foot by the Achilles tendon and R is the force exerted on the foot by the tibia. Find the values of T, R, and when Fg = 700 N. Figure P12.32arrow_forwardIn the short story The Pit and the Pendulum by 19th-century American horror writer Edgar Allen Poe, a man is tied to a table directly below a swinging pendulum that is slowly lowered toward him. The bob of the pendulum is a 1-ft steel scythe connected to a 30-ft brass rod. When the man first sees the pendulum, the pivot is roughly 1 ft above the scythe so that a 29-ft length of the brass rod oscillates above the pivot (Fig. P16.39A). The man escapes when the pivot is near the end of the brass rod (Fig. P16.39B). a. Model the pendulum as a particle of mass ms 5 2 kg attached to a rod of mass mr 5 160 kg. Find the pendulums center of mass and rotational inertia around an axis through its center of mass. (Check your answers by finding the center of mass and rotational inertia of just the brass rod.) b. What is the initial period of the pendulum? c. The man saves himself by smearing food on his ropes so that rats chew through them. He does so when he has no more than 12 cycles before the pendulum will make contact with him. How much time does it take the rats to chew through the ropes? FIGURE P16.39arrow_forward
- When a circus performer performing on the rings executes the iron cross, he maintains the position at rest shown in Figure P12.37a. In this maneuver, the gymnasts feet (not shown) are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi (lats) and the pectoralis major (pecs). One of the rings exerts an upward force Fk on a hand as show n in Figure P12.37b. The force Fs, is exerted by the shoulder joint on the arm. The latissimus dorsi and pectoralis major muscles exert a total force Fm on the arm. (a) Using the information in the figure, find the magnitude of the force Fm for an athlete of weight 750 N. (b) Suppose a performer in training cannot perform the iron cross but can hold a position similar to the figure in which the arms make a 45 angle with the horizontal rather than being horizontal. Why is this position easier for the performer? Figure P12.37arrow_forwardA spring 1.50 m long with force constant 475 N/m is hung from the ceiling of an elevator, and a block of mass 10.0 kg is attached to the bottom of the spring. (a) By how much is the spring stretched when the block is slowly lowered to its equilibrium point? (b) If the elevator subsequently accelerates upward at 2.00 m/s2, what is the position of the block, taking the equilibrium position found in part (a) as y = 0 and upwards as the positive y-direction. (c) If the elevator cable snaps during the acceleration, describe the subsequent motion of the block relative to the freely falling elevator. What is the amplitude of its motion?arrow_forwardThe steel system consists of rod CD, rod AB and a rigid bar AC. The diameter of rods CD and AB are 16 mm and 18 mm, 2.0 m T respectively. If a force of 30 kN is applied to point E, determine: a) the normal stress in rod AB and DC, b) the horizontal displacement of point E. Est = 200 GPa. 0.6 m E 0.3 m 30 kN B 4.0 m Aarrow_forward
- A copper wire of length 3 m has a diameter 1 mm. If weight of 10 kg is attached to one end of wire, what is the extension produced? Calculate lateral contraction if poisson's ratio is 0.25 (Y=12.5 x 10¹⁰ N/m²)arrow_forwardA solid copper cube has an edge length of 89.6 cm. How much stress must be applied to the cube to reduce the edge length to 89 cm? The bulk modulus of copper is 1.4 x 1011 N/m². Number i 27.94 Units N/m^2 or Paarrow_forward. A copper wire LM is fused at one end, M to an iron wire MN as shown in figure below. L M N F The copper wire has length 0.90 m and cross-section area 0.90 x10-6 m². The iron wire has length 1.40 m and cross-section area 1.30 x10-6 m2. The compound wire is stretched and the total length increases by 0.01 m. Given Yiron = 2.10 x1011 Pa and Give Ycopper = 1.30 x1011 Pa. Determine %3D %3! a. the ratio of the extension of copper wire to the extension of iron wire,arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning