2.52.There is a whistle attached to each end of a 3.4m long stick. As shown in the picture on the right, the bar rotates at an angular speed of 20 rad/s in the horizontal plane with the line passing through the center of the bar as the axis. What is the maximum number of beats per second observed by a person far away from this bar? (However, the vibration frequency of the sound coming from the whistle is 99Hz, and the speed of sound is 340m/s.) N=rw=34m/ дан 20 rows/s w = 20 rad/s

A screwdriver is dropped from the top of an elevator shaft. Exactly 5.0 seconds later, the sound of the screwdriver hitting bottom is heard. How deep is the shaft? The shaft is approximately (Round to the nearest tenth.) feet deep. Hint: The distance that a dropped object falls in t seconds is represented by the formula s = 16t². The speed of sound is 1100 ft/sec.

A bat flying at 5.05 m/s is chasing an insect flying in the same direction. The bat emits a 39.8-kHz chirp and receives back an echo at 40.6 kHz. (Take the speed of sound in air to be v = 343 m/s.) (a) What is the speed of the insect? m/s(b) Will the bat be able to catch the insect? Yes No     Explain.

Porpoises emit sound waves that they use for navigation. If the wavelength of the sound wave emitted is 4.5 cm, and the speed of sound in the water is v = 1530 m/s, what is the period of the sound?

In taking your pulse, you count 75 heartbeats in 1 min. What are the period (in s) and frequency (in Hz) of your heart’s oscillations?

Pr5. Two identical loudspeakers are located at points (-10,0,0) and (0,0, 10) of our coor- dinate system, where the numbers in the brac- kets correspond to the (r, y, z) coordinates of the points, expressed in meters. The loudspeakers are driven by the same oscillator with a frequ- ency of 170 Hz. The speed of sound in air can be considered 340 m/s. a) Give the coordinates of those points loca- ted on the positive r axis where the sound waves coming from the two loudspeakers interfere con- structively. b) A receiver is started to move slowly from the origin (0,0,0) along a path lying in the r-y plane so that it receives constant sound intensity throughout its slow motion. What is the shape of the path the receiver should take?

Please ONLY answer 2d and 2e 2a. A mass moving back and forth on a spring obeys the sinusoidal equation x(t) = A cos(2πft), where A is the amplitude of the oscillation or the maximum displacement of the mass from its equilibrium position, f is the frequency of the oscillation and t is the time. If the amplitude is 10.0 cm and the frequency is f = 0.500 Hz, what is the position of the mass at t = 3.00 s? 2b. The velocity of the mass is also a sinusoidal function with the same period and frequency: v(t) = -vmax sin(2πft). Calculate vmax and the velocity of the mass v(t) when t = 3.00 s. 2c. What is the period T of this oscillation? 2d. If you evaluate the position function at t = 0 s the cosine of zero is 1 so you get the maximum amplitude of the oscillation, A. This occurs at the maximum stretch of the spring from its equilibrium position. For a mass on a spring this corresponds to the maximum spring potential energy, and because the velocity is zero at the endpoints of the oscillation,…

The motion of a particle is described by y = (0.05 m) sin(20 rad t), where y is in meters and tis in seconds. What is the frequency of the motion of the particle? O 3 Hz O 2 Hz O 1 Hz O 4 Hz

What is the period, in seconds, that corresponds to each of the following frequencies: (a) 10 Hz, (b) 0.2 Hz, (c) 60 Hz?

A pendulum completes 75 swings in 25 s. What is its frequency? 3.0 s 0.33 Hz O 3.0 Hz O0.33 s None of the above