91Ó°ÊÓ

A hummingbird's wings vibrate at about \(45 \mathrm{~Hz}\). What's the corresponding period?

A particle undergoes simple harmonic motion with amplitude \(27 \mathrm{~cm}\) and maximum speed \(4.6 \mathrm{~m} / \mathrm{s}\). Find the (a) angular frequency, (b) period, and (c) maximum acceleration.

A wheel rotates at \(720 \mathrm{rpm}\). Viewed from the edge, a point on the wheel appears to undergo simple harmonic motion. What are (a) the frequency in \(\mathrm{Hz}\) and (b) the angular frequency for this SHM?

A mass-spring system is oscillating with frequency \(f=0.377 \mathrm{~Hz}\) and amplitude \(28.2 \mathrm{~cm}\). Find its speed at the point where its kinetic and potential energies are equal

A mass-spring system with spring constant \(k=63.7 \mathrm{~N} / \mathrm{m}\) is oscillating with angular frequency \(2.38 \mathrm{~s}^{-1}\) and total energy \(7.69 \mathrm{~J}\). Find (a) its amplitude and (b) its maximum speed.

A simple pendulum of mass \(m\) is swinging with period \(T\) and amplitude \(\theta_{\max }\). Find expressions for (a) its total energy and (b) its maximum speed.

an ornithologist who knows you've studied physics. She asks you for a noninvasive way to measure birds" masses. You propose using a bird feeder in the shape of a 50 -cm-diameter disk of mass \(340 \mathrm{~g}\), suspended by a wire with torsional constant \(5.00 \mathrm{~N} \cdot \mathrm{m} / \mathrm{rad}(\mathrm{Fig} .13 .35)\). Two birds land on opposite sides and the feeder goes into torsional oscillation at \(2.6 \mathrm{~Hz}\). Assuming the birds have the same mass, what is it?