Ask question

Ask question

All categories

3 years ago

11

Dogs are able to hear much higher frequencies then humans are capable of detecting. For this reason the crystals that are inaudi

ble to the human ear can be heard easily by a dog. If a dog whistle has a frequency of 3.0 x 10^4 Hz, what is the wavelength of the sound emitted?

1 answer:

AVprozaik [17]3 years ago

3 0

Answer:

Dogs are able to hear much higher frequencies than humans are capable of detecting. For this reason, dog whistles that are inaudible to the human ear can be heard easily by a dog. If a dog whistle has a frequency of 30,000 Hz, what is the wavelength of the sound emitted?

You might be interested in

What is the volume of a box that is 12 cm long, 2 cm wide, and 3 cm high?

Fofino [41]

12 cm x 2 cm x 3 cm = 72 cm3

3 0

3 years ago

A large aquarium of height 6 m is filled with fresh water to a depth of D = 1.50 m. One wall of the aquarium consists of thick p

Vesnalui [34]

Answer

given,

height of aquarium = 6 m

Depth of fresh water = D = 1.50 m

horizontal length of the aquarium(w) = 8.40 m

total force increased when liquid is filled to depth = 4.30 m

g = 9.81 m/s²

ρ = 998 Kg/m³

force in the aquarium.

dF = PdA

$F = \int PdA$

$F = \int \rho\ g\ y\ (wdy)$

$F = \rho\ g\ w \int ydy$

$F = \rho\ g\ w\dfrac{y^2}{2}$

$F = \dfrac{\rho\ g\ w\ y^2}{2}$

At D = 1.5 m

$F = \dfrac{980\times 9.8\times 8.4\times 1.5^2}{2}$

F = 9.08 x 10⁴ N

At D = 4.30 m

$F = \dfrac{980\times 9.8\times 8.4\times 4.3^2}{2}$

F = 7.46 x 10⁵ N

Total force on the wall increased by

ΔF = 74.6 x 10⁴ - 9.08 x 10⁴

ΔF = 65.52 x 10⁴ N

5 0

3 years ago

Fine grains of beach sand are assumed to be spheres of radius 64.8 µm. These grains are made of silicon dioxide which has a dens

Nutka1998 [239]

Answer:

1) Mass of the grain is $2.9632\times 10^{-9} kg$ .

2) 0.08901 kg of sand would have surface area equal the surface area of the cube.

Explanation:

1) Radius of the grain,r = 64.8 µm = $6.48\times 10^{-5}m$

Volume of the sphere = $\frac{4}{3}\pi r^3$

Volume of the grain of a sand:

$V=\frac{4}{3}\times \pi r^3=\frac{4}{3}\times 3.14\times (6.48\times 10^{-5} m)^3$

$V=1.1397\times 10^{-12} m^3$

Density of a grain of sand = $d=2600 kg/m^3$

Mass of a grain of a sand = M

$d=2600 kg/m^3=\frac{M}{1.1397\times 10^{-12} m^3}$

$M=2.9632\times 10^{-9} kg$

Mass of the grain is $2.9632\times 10^{-9} kg$ .

2) Surface are of sphere: $4\pi r^2$

Surface area of a grain:

$A=4\times 3.14\times (6.48\times 10^{-5}m)^2$

$A=5.2766\times 10^{-8} m^2$

Length of the cube = a = 0.514 m

Total surface area of cube ,A'= $6a^2$

$A'=6\times (0.514 m)^2=1.5851 m^2$

let the number grains with area equal to total surface area of cube be x.

$A'=A\times x$

$x=\frac{1.5851 m^2}{5.2766\times 10^{-8} m^2}=3.003\times 10^7$

Volume of x number of grains :V'

$V'=V\times x$

$V= 1.1397\times 10^{-12} m^3\times 3.003\times 10^7$

$V'=3.4236\times 10^{-5} m^3$

Mass of $3.4236\times 10^{-5} m^3$ of sandL:

= $3.4236\times 10^{-5} m^3\times 2600 kg/m^3=0.08901 kg$

0.08901 kg of sand would have surface area equal the surface area of the cube.

8 0

3 years ago

A 50-cm-long spring is suspended from the ceiling. A 330g mass is connected to the end and held at rest with the spring unstretc

Anvisha [2.4K]

Explanation:

Given that,

Length of the spring, l = 50 cm

Mass, m = 330 g = 0.33 kg

(A) The mass is released and falls, stretching the spring by 28 cm before coming to rest at its lowest point. On applying second law of Newton at 14 cm below the lowest point we get :

$kx=mg\\\\k=\dfrac{mg}{x}\\\\k=\dfrac{0.33\times 9.8}{0.14}\\\\k=23.1\ N/m$

(B) The amplitude of the oscillation is half of the total distance covered. So, amplitude is 14 cm.

(C) The frequency of the oscillation is given by :

$f=\dfrac{1}{2\pi}\sqrt{\dfrac{k}{m}} \\\\f=\dfrac{1}{2\pi}\sqrt{\dfrac{23.1}{0.33}} \\\\f=1.33\ Hz$

5 0

4 years ago

Give an example of a collision in real life. Use the law of conservation of energy to describe the transfer of momentum. Be sure

ozzi

Explanation :

Using the law of conservation of energy

When two cars collide with each other then the momentum is same before collision and after collision but energy is changed after collision in form of heat and sound.

We know this collision is inelastic collision.

In Inelastic collision, when two objects collide with each other then the momentum is conserved but kinetic energy is not conserved.

7 0

4 years ago