Concept explainers
The lowest new fundamental frequency.
Answer to Problem 79AP
The lowest new fundamental frequency is
Explanation of Solution
Write the relation between mass and density.
Here,
Write the expression for tension in the wire.
Here,
Write the expression for buoyant force exerted by water on the copper object
Here,
Write the relation between frequency, wavelength and velocity for string
Here,
Write the relation between frequency, wavelength and velocity for changed string.
Here,
Write the expression for speed of wave on the string.
Here,
Write the expression for speed of wave on the new string.
Here,
Conclusion:
Substitute equation (I) in equation (II)
The reduced tension of the object, when submerged in water is,
Substitute the equation (III) and (VIII) in above equation.
Substitute equation (VI) in equation (IV) and equation (VII) in (V).
Divide the above two equations.
Substitute the equation (VIII) and (IX) in above equation and rearrange for
Substitute
Therefore, the lowest new fundamental frequency is
Want to see more full solutions like this?
Chapter 18 Solutions
Physics for Scientists and Engineers with Modern Physics Technology Update
- If you blow across the top of an empty soft-drink bottle, a pulse of sound travels down through the air in the bottle. At the moment the pulse reaches the bottom of the bottle, what is the correct description of the displacement of elements of air from their equilibrium positions and the pressure of the air at this point? (a) The displacement and pressure are both at a maximum. (b) The displacement and pressure are both at a minimum. (c) The displacement is zero, and the pressure is a maximum. (d) The displacement is zero, and the pressure is a minimum.arrow_forwardIn about 1657, Otto von Guericke, inventor of the air pump, evacuated a sphere made of two brass hemispheres (Fig. P15.62). Two teams of eight horses each could pull the hemispheres apart only on some trials and then with greatest difficulty, with the resulting sound likened to a cannon firing. Find the force F required to pull the thin-walled evacuated hemispheres apart in terms of R, the radius of the hemispheres; P, the pressure inside the hemispheres; and atmospheric pressure P0. Figure P15.62arrow_forwardAs shown in Figure P14.37, water is pumped into a tall, vertical cylinder at a volume flow rate R. The radius of the cylinder is r, and at the open top of the cylinder a tuning fork is vibrating with a frequency f. As the water rises, what time interval elapses between successive resonances? Figure P14.37 Problems 37 and 38.arrow_forward
- A room contains air in which the speed of sound is 343 m/s. The walls of the room are made of concrete, in which the speed of sound is 1 850 m/s. Find the critical angle for total internal reflection of sound at the concrete−air boundaryarrow_forwardYou are watching a pier being constructed on the far shore of a saltwater inlet when some blasting occurs. You hear the sound in the water 2.86 s before it reaches you through the air. How wide is the inlet? Assume the temperature is 20 degrees C, the speed of sound in air at 0 degrees C is 331 m/s, and the speed of sound in saltwater is 1530 m/s. Answer in units of km.arrow_forwardA sound wave arriving at your ear is transferred to the fluid in the cochlea. If the intensity in the fluid is 0.410 times that in air and the frequency is the same as for the wave in air, what will be the ratio of the pressure amplitude of the wave in air to that in the fluid? Approximate the fluid as having the same values of density and speed of sound as water. Speed of sound in dry air (20.0°C, 1.00 atm) is 343 m/s, density of dry air (at STP) is 1.29 kg/m3, density of water is 1000 kg/m3, and speed of sound in water is 1493 m/s.arrow_forward
- Calculate the time taken by a sound wave of frequency 800 Hz and wavelength 44 cm to travel a distance of 500 m. What would be the atmospheric temperature in dry air in this situation? How about the atmospheric (air) bulk modulus Bair ? Given : Density of air (ρair) = 1.92 kg/m3.arrow_forwardA well with vertical sides and water at the bottom resonates at 7.00 Hz and at no lower frequency. (The air filled portion of the well acts as a tube with one closed end and one open end.) The air in the well has a density of 1.10 kg/m^3 and a bulk modulus of 1.33×10^5 Pa. How far down in the well is the water surface?arrow_forwardA tuning fork that vibrates at a frequency 680 Hz is placed over an 80 centimeter long cylinder that is completely filled with water. The water is then allowed to drain out, creating an air column of varying length above the surface of the water and inside the cylinder. Find the distances d between the top of the cylinder and the surface of the water for which the air column will resonate at 680 Hz. Assume that the speed of sound is 340 m/s.arrow_forward
- The water level in a vertical glass tube 1.00 m long can be adjusted to any position in the tube. A tuning fork vibrating at 686 Hz is held just over the open top end of the tube, to set up a standing wave of sound in the air-filled top portion of the tube. (That airfilled top portion acts as a tube with one end closed and the other end open.) (a) For how many different positions of the water level will sound from the fork set up resonance in the tube’s air-filled portion? What are the (b) least and (c) second least water heights in the tube for resonance to occur?arrow_forwardCalculate the pressure amplitude (in m) of a 45 kHz sound wave in pure hydrogen if it has adisplacement amplitude of 1.5 mm. (ρH2 = 0.08 kg/m3, v = 1286 m/s.)arrow_forwardTwo loudspeakers directly face each other 30 m apart, with the left speaker positioned at x = 0 m. The pressure of the sound wave emitted by the left speaker is described by the equation ΔpL = p0 cos(1.90x - 630t), while that from the right speaker is given by ΔpR = p0 cos(1.90x + 630t), where x ismeasured in m and t in s. What is the point nearest to the left speaker at which there is a node in the sound wave?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning