An iron block is dropped into a deep well. Sound of splash is heard after $4.23 \,s$. If the depth of the well is $78.4 \,m$, then find the speed of sound in air is ............ $m / s$ $\left(g=9.8 \,m / s ^2\right)$
Medium
Download our app for free and get started
(a)
Assuming no air (or air drag) on stone, the time it takes stone to reach water is:
$t =\sqrt{2 h / g} =\sqrt{2(78.4) / 9.81}=\sqrt{15.98369}=3.998\,s$
time for sound to travel $78.4\,m =4.23-3.998=0.232\,s$
speed of sound in well $=78.4 / 0.232=338\,m / s$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1Out of the given four waves $(1), (2), (3)$ and $(4)$View Solution
$y = a\sin (kx + \omega t)$ ......$(1)$
$y = a\sin (\omega t - kx)$ ......$(2)$
$y = a\cos (kx + \omega t)$ ......$(3)$
$y = a\cos (\omega t - kx)$ ......$(4)$
emitted by four different sources ${S_1},\,{S_2},\,{S_3}$ and ${S_4}$ respectively, interference phenomena would be observed in space under appropriate conditions when
- 2Transverse wave propagates in a medium with a velocity of $1450\,m/s$ . The distance between the nearest points at which the oscillations of the particles carried in the opposite phase $\pi $ is $0.1\,m$ . What is the frequency of the wave ..... $Hz$ ?View Solution
- 3The ends of a stretched wire of length $L$ are fixed at $x = 0$ and $x = L.$ In one experiment, the displacement of the wire is ${y_1} = A\sin (\pi x/L)\sin \omega t$ and energy is ${E_1}$, and in another experiment its displacement is ${y_2} = A\sin (2\pi x/L)\sin 2\omega t$ and energy is ${E_2}$. ThenView Solution
- 4A mass of $20\ kg$ is hanging with support of two strings of same linear mass density. Now pulses are generated in both strings at same time near the joint at mass. Ratio of time, taken by a pulse travel through string $1$ to that taken by pulse on string $2$ isView Solution
- 5When a wave travels in a medium, the particle displacements are given by $y = a\, sin\, 2\pi\, (bt -cx)$ where $a, b,$ and $c$ are constants. The maximum particle velocity will be twice the wave velocity ifView Solution
- 6A stationary source emits sound of frequency $\mathrm{f}_0=492 \mathrm{~Hz}$. The sound is reflected by a large car approaching the source with a speed of $2 \mathrm{~ms}^{-1}$. The reflected signal is received by the soruce and superposed with the original. What will be the beat frequency of the resulting signal in $\mathrm{Hz}$ ? (Given that the speed of sound in air is $330 \mathrm{~ms}^{-1}$ and the car reflects the sound at the frequency it has received).View Solution
- 7$Assertion :$ When a beetle moves along the sand within a few tens of centimeters of a sand scorpion, the scorpion immediately turns towards the beetle and dashes towards itView Solution
$Reason :$ When a beetle disturbs the sand, it sends pulses along the sand's surface. One set of pulses is longitudinal while the other set is transverse. - 8A police car moving at $22 m/s$, chases a motorcyclist. The police man sounds his horn at $176 Hz$, while both of them move towards a stationary siren of frequency $165 Hz$. Calculate the speed of the motorcycle, if it is given that he does not observes any beats .... $m/s$View Solution
- 9An observer standing near the sea shore observes $54$ waves per minute. If the wavelength of the water wave is $10m$ then the velocity of water wave is .... $ms^{-1}$View Solution
- 10Consider the three wavesView Solution
${z_1},{z_2}$ and ${z_3}$ as${z_1} = A\sin (kx - \omega \,t)$, ${z_2} = A\sin (kx + \omega \,t)$ and ${z_3} = A\sin (ky - \omega \,t)$.
Which of the following represents a standing wave