Ask question

Ask question

All categories

White raven [17]

3 years ago

5

A 90.0-m-long brass rod is struck at one end. A person at the other end hears two sounds as a result of two longitudinal waves,

one traveling in the metal rod and the other traveling in the air. What is the time interval between the two sounds? Take the speed of sound in air to be 344 m/s. Use 8600 kg/m3 for the density of brass and 9.00×109 Pa for Young's modulus of brass.

1 answer:

Zanzabum3 years ago

6 0

Answer:

0.174413400763 s

Explanation:

L = Length of rod = 90 m

Speed of sound in air = 344 m/s

$\rho$ = Density of brass = 8600 kg/m³

Y = Young's modulus = $9\times 10^9\ Pa$

Velocity of sound in a material is given by

$v_b=\sqrt{\dfrac{Y}{\rho}}\\\Rightarrow v_b=\sqrt{\dfrac{9\times 10^9}{8600}}\\\Rightarrow v_b=1022.99150921\ m/s$

Time taken in brass

$t=\dfrac{L}{v_b}\\\Rightarrow t=\dfrac{90}{1022.99150921}\\\Rightarrow t=0.0879772697913\ s$

In air

$t=\dfrac{L}{v}\\\Rightarrow t=\dfrac{90}{343}\\\Rightarrow t=0.262390670554\ s$

The time interval is $0.262390670554-0.0879772697913=0.174413400763\ s$

You might be interested in

How can you use your personal choices to exercise more safely

vagabundo [1.1K]

Not exercising in high-air pollution areas
limiting exercise in hot climates to the early morning and evening
using exercise equipment as it was designed to be used

4 1

3 years ago

Which statement best describes the circular flow model?

aleksley [76]

Can you please include the statement or the model?

3 0

2 years ago

Two coaxial conducting cylindrical shells have equal and opposite charges. The inner shell has charge +q and an outer radius a,

Leviafan [203]

Answer:

$\Delta V = \frac{q ln(\frac{b}{a})}{2\pi \epsilon_0 L}$

Explanation:

As we know that the charge per unit length of the long cylinder is given as

$\lambda = \frac{q}{L}$

here we know that the electric field between two cylinders is given by

$E = \frac{2k\lambda}{r}$

now we know that electric potential and electric field is related to each other as

$\Delta V = - \int E.dr$

$\Delta V = -\int_a^b (\frac{2k\lambda}{r})dr$

$\Delta V = -2k \lambda ln(\frac{b}{a})$

$\Delta V = \frac{\lambda ln(\frac{b}{a})}{2\pi \epsilon_0}$

$\Delta V = \frac{q ln(\frac{b}{a})}{2\pi \epsilon_0 L}$

7 0

3 years ago

A mountain-climber friend with a mass of 74 kg ponders the idea of attaching a helium-filled balloon to himself to effectively r

bazaltina [42]

Answer:

$V=16.65 m^3$

Explanation:

The volume of the balloon can be find compared the force in each cases so:

reduce 25% from 74kg

$R=\frac{25}{100}*74kg=18.5kg$

So the net force uproad on the balloon is

$F_b=18.5kg*g$

Now the density of the both gases air and helium are different however the volume is the same change offcorss the mass so:

$P_h=\frac{m}{V}=0.179 kg/m^3$

$P_A=1.29 kg/m^3$

$F_b=F_A-F_H$

$F_b=m_a*g-m_h*g$

$m=P/V$

$18.5kg*g=(1.29kg/m^3-0.179kg/m^3*)V*g$

$V=\frac{18.5kg}{(1.29-0.179)kg/m^3}$

$V=16.65 m^3$

4 0

3 years ago

When two sticks are laid end-to-end they cover a length of 8.32 feet. One stick is 2.93 ft longer than the other. What is the le

77julia77 [94]

To solve this problem we will start by defining the length of the shortest stick as 'x'. And the magnitude of the longest stick, according to the statement as

$x+2.93$

Both cover a magnitude of 8.32 ft, therefore

$x +(x+2.97) = 8.32$

Now solving for x we have,

$x + (x + 2.93) = 8.32$

$2x + 2.93 = 8.32$

$2x = 8.32 - 2.93$

$x = \frac{ 8.32 - 2.93}{2}$

$x = 2.695 ft$

Therefore the shorter stick is 2.695ft long.

7 0

3 years ago