Exam 15: Mechanical Waves

A heavy stone of mass m is hung from the ceiling by a thin 8.25-g wire that is 65.0 cm long.When you gently pluck the upper end of the wire,a pulse travels down the wire and returns 7.84 ms later,having reflected off the lower end.The stone is heavy enough to prevent the lower end of the wire from moving.What is the mass m of the stone?

A guitar string is fixed at both ends.If you tighten it to increase its tension

The figure shows the displacement y of a traveling wave at a given position as a function of time and the displacement of the same wave at a given time as a function of position.Determine the wavelength of the wave.

You and your surfing buddy are waiting to catch a wave a few hundred meters off the beach.The waves are conveniently sinusoidal,and you notice that when you're on the top of one wave and moving toward your friend,she is exactly halfway between you and the trough of the wave.1.50 seconds later,your friend is at the top of the wave.You estimate the horizontal distance between you and your friend at 8.00 m. (a)What is the frequency of the waves? (b)Find the speed of the waves.

Find the speed of an ocean wave whose vertical displacement y as a function of time t is given by ,where all quantities are in SI units.

Four traveling waves are described by the following equations,where all quantities are measured in SI units and y represents the displacement. I: y = 0.12 cos(3x - 21t) II: y = 0.15 sin(6x + 42t) III: y = 0.13 cos(6x + 21t) IV: y = -0.27 sin(3x - 42t) Which of these waves have the same period?

A tiny vibrating source sends waves uniformly in all directions.An area of 3.25 cm² on a sphere of radius 2.50 m centered on the source receives energy at a rate o /s. (a)What is the intensity of the waves at 2.50 m from the source and at 10.0 m from the source? (b)At what rate is energy leaving the vibrating source of the waves?

The figure shows the displacement y of a wave at a given position as a function of time and the displacement of the same wave at a given time as a function of position.Determine the frequency of the wave.

In the figure,which of the curves best represents the variation of wave speed as a function of tension for transverse waves on a stretched string?

A transverse wave traveling along a string transports energy at a rate r.If we want to double this rate,we could

A 8.0-m long wire with a mass of 10 g is under tension.A transverse wave for which the frequency is ,the wavelength is ,and the amplitude is is propagating on the wire.The maximum transverse acceleration of a point on a wire is closest to

A standing wave is oscillating at 690 Hz on a string,as shown in the figure.What is the speed of traveling waves on this string?

A thin 2.00-m string of mass 50.0 g is fixed at both ends and under a tension of 70.0 N.If it is set into small-amplitude oscillation,what is the frequency of the first harmonic mode?

Observer A is 3.0 m from a tiny light bulb and observer B is 12.0 m from the same bulb.Assume that the light spreads out uniformly and undergoes no significant reflections or absorption.If observer B sees a light of intensity I,the light intensity that A sees is

A wave pulse traveling to the right along a thin cord reaches a discontinuity where the rope becomes thinner and lighter.What is the orientation of the reflected and transmitted pulses?

You are generating traveling waves on a stretched string by wiggling one end.If you suddenly begin to wiggle more rapidly without appreciably affecting the tension,you will cause the waves to move down the string

The intensity of sunlight falling on the earth is about 1.4 kW/m² (before any gets absorbed by our atmosphere).At what rate does the sun emit light energy? (The earth-sun distance = 1.5 × 10⁸ km and the earth's radius = 6.4 × 10³ km.)

When a weight W is hanging from a light vertical string,the speed of pulses on the string is V.If a second weight W is added without stretching the string,the speed of pulses on this string will now become

A guitar string 0.650 m long has a tension of 61.0 N and a mass per unit length of 3.00 g/m. (a)What is the speed of waves on the string when it is plucked? (b)What is the string's fundamental frequency of vibration when plucked?

For the wave shown in the figure,the frequency is