Download App

Sound — Physics STD 10 — Question

ICSE BoardEnglish MediumSTD 10PhysicsSound3 Marks
Question
 A rifle shot is fired in a valley between two parallel walls. The echo from one wall is heard in 3 s and the echo from the other wall is heard 3 s later. If the velocity of sound at 00 c is $330 ms^{-1}$ and the temperature in the valley is 100 c , calculate the width of the valley. For every 10 c rise in temperature, the velocity of sound increase by $0.61 ms^{-1}$.
✓

Answer

Give that, speed of sound at $0^{\circ}=330 \mathrm{~m} / \mathrm{s}$
For every $1^{\circ}$ rise in temperature, the velocity of sound increases by $0.61 \mathrm{~m} / \mathrm{s}$ $\therefore$ the velocity of sound at $10^{\circ}=330+(0.61 \times 10)=330+6.1=336.1 \mathrm{~m} / \mathrm{s}$
Let $A_1$ and $A_2$ be the distances of the two walls from the point of refile shots. Then
$ \begin{aligned} & 2 \times A_1=336.1 \times 3=1008.3 ...........(i) \\ & 2 \times A_2=336.1 \times 6=2016.6 ...........(ii) \end{aligned} $
Adding (i) and (ii) we get
$ 2\left(A_1+A_2\right)=3024.9 $
or, $\left(A_1+A_2\right)=1512.45 \mathrm{~m}$
Thus the width of the velley is $1512.45 \mathrm{~m}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "[3 Mark Question Answer]" from Sound→Sound — all question types→Physics STD 10 question papers→ICSE Board STD 10 question papers→ICSE Board question paper generator→

Similar questions

The danger signal is red. Why?
→
The frequency range of visible light is from $3.75 \times 10^{14} Hz \rightarrow 7.5 x 10^{14} Hz$ Calculate its wavelength range. Take speed of light $=3 \times 10^8 m / s ^{-1}$
→
The magnification by a lens is -3. Name the lens and state how are u and v related?
→
In the diagram below, XX’ represents the principal axis, O the optical centre and F the focus of the lens. Complete the path of rays A and B as they emerge out of the lens.

→
In fig. P, Q, R and S are four pendulums suspended from the same elastic string XX'. Lengths of pendulum P and S are equal, while the length of Q is smaller and R is longer. The pendulum P is set into vibration. What is your observation? Give reason for your observation.
→
Give three examples for leavers of the third order.
→
State the class of levers and the relative positions of load (L) effort (E) and fulcrum (F) in sugar tongs.
→

The following diagram shows the path taken by a narrow beam of yellow monochromatic light passing through an equiangular glass prism. Now the yellow light is replaced by a narrow beam of white light incident at the same angle. Draw another diagram to show the passage of white light through the prism and label it to show the effect of prism on the white light.

→
Usually three insulated wires of different colours are used in an electrical appliance. Name the three colours.
→
Ice-cream at 0°C feels colder than water at 0°C. Give reason for this observation.
→