Concept explainers
You’re working for a playground equipment company, which wants to know the rotational inertia of its swing with a child on board: the combined mass is 20 kg. You observe the child twirling around in the swing, twisting the ropes as shown in Fig. 13.37. As a result, child and swing rise slightly, with the rise h in cm equal to the square of the number of full turns. When the child stops twisting, the swing begins torsional oscillations. You measure the period at 6.91 s. What do you report for the rotational inertia of the child-swing system?
FIGURE 13.37 Problem 84
Want to see the full answer?
Check out a sample textbook solutionChapter 13 Solutions
Essential University Physics
Additional Science Textbook Solutions
University Physics Volume 2
College Physics (10th Edition)
College Physics: A Strategic Approach (4th Edition)
Applied Physics (11th Edition)
The Cosmic Perspective Fundamentals (2nd Edition)
Physics: Principles with Applications
- The angular frequency of a simple harmonic oscillator is 1.4x106 rad/s. Its period is about:arrow_forwardIn a pendulum, is it angular velocity or angular acceleration that is proportional to sin (theta)?arrow_forwardThe piston in the cylinder head of a V8 engine has a stroke (twice the amplitude) of 2.0 m. Given that the piston moves with simple harmonic motion at an angular frequency of 400 rad/min, find its maximum speed?arrow_forward
- How much torque must be applied to a 6.0 kg flywheel with a diameter of 30 cm, that is in a shape of a solid circular plate, to change its frequency from 1000 min-1 to 2500 min-1?arrow_forwardA mass of 11.1 kg, fastened to the end of an aluminum wire with an unstretched length of 0.54 m , is whirled in a vertical circle with a constant angular speed of 116 rev/min. The cross-sectional area of the wire is 1.5×10−2 cm^2. A. Calculate the elongation of the wire when the mass is at the lowest point of the path. B. Calculate the elongation of the wire when the mass is at the highest point of its path.arrow_forwardThe upper surface of a cube of gelatin, 5.0 cm on a side, is displaced by 0.64 cm by a tangential force. If the shear modulus of the gelatin is 940 Pa, what is the magnitude of the tangential force?arrow_forward
- The energy stored per uni volume in copper wire which produces longitudinal strain of 0.1% is Y=1.1 x 1011 N/m2arrow_forwardA 10kg load suspended by a brass wire 10m long is observed to vibrate vertically in SHM at a frequency of 10 vib/s. Given that the Young's modulus for brass is 9 x 10^10 N/m^2, what is the cross-sectional area of the wire?arrow_forwardA simple pendulum of length 20 cm and mass 5.0 g is suspended in a race car traveling with constant speed 70 m/s around a circle of radius 50 m. If the pendulum undergoes small oscillations in a radial direction about its equilibrium position, what is the frequency of oscillation?arrow_forward
- A 73 m length with a radius of 2.3 m of a cylinder supports a 9.5 x 10 5 kg mass which presses down thecylinder at a modulus of 9.4 x 10 10 N/m 11. What is the downward deflection of the cylinder?arrow_forwardA simple pendulum with mass m = 1.2 kg and length L = 2.48 m hangs from the ceiling. It is pulled back to an small angle of θ = 11° from the vertical and released at t = 0. a) What is the angular displacement at t = 3.54 s? (give the answer as a negative angle if the angle is to the left of the vertical) b) What is the magnitude of the radial acceleration as the pendulum passes through the equilibrium position?arrow_forwardA 95 kg solid sphere with a 15 cm radius is suspended by a vertical wire. A torque of 0.20 Nm is required to rotate the sphere through an angle of 0.85 rad and then maintain that orientation. What is the period of the oscillations that result when the sphere is then released?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning