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3 years ago

• What affects the speed of sound?

Physics

1 answer:

suter [353]3 years ago

6 0

Answer:

The material effects the speed if sound.

Explanation:

A denser material whose atoms are tightly packed will quickly transfer energy as they are close to each other than mediums like air.

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Which of these statements are true about hydroelectric power? A.It is the most widely used renewable energy source in the world.

Ede4ka [16]

D is the answer most true

6 0

3 years ago

A very thin circular disk of radius R = 20.00 cm has charge Q = 30.00 mC uniformly distributed on its surface. The disk rotates

lutik1710 [3]

Answer:

$B= 7.5*10^{-15}T$

Explanation:

The magnetic field strenght on the z-axis at a distance d from the center is,

$B= \frac{\mu_0 Q\omega R^2}{8\pi d^3}$

Our values are:

$R=20cm\\Q=30mc\\w=5rad/s\\d=2*10^3cm=20m$

Replacing,

$B= \frac{(4\pi*10^{}-7)(30*10^{-3})(5)(0.2)^2}{8\pi(20)}$

$B= 7.5*10^{-15}T$

3 0

3 years ago

When UV light of wavelength 248 nm is shone on aluminum metal, electrons are ejected withmaximum kinetic energy 0.92 eV. What ma

Lina20 [59]

Answer:

The maximum wavelength of light that could liberate electrons from the aluminum metal is 303.7 nm

Explanation:

Given;

wavelength of the UV light, λ = 248 nm = 248 x 10⁻⁹ m

maximum kinetic energy of the ejected electron, K.E = 0.92 eV

let the work function of the aluminum metal = Ф

Apply photoelectric equation:

E = K.E + Ф

Where;

Ф is the minimum energy needed to eject electron the aluminum metal

E is the energy of the incident light

The energy of the incident light is calculated as follows;

$E = hf = h\frac{c}{\lambda} \\\\where;\\\\h \ is \ Planck's \ constant = 6.626 \times 10^{-34} \ Js\\\\c \ is \ speed \ of \ light = 3 \times 10^{8} \ m/s\\\\E = \frac{(6.626\times 10^{-34})\times (3\times 10^8)}{248\times 10^{-9}} \\\\E = 8.02 \times 10^{-19} \ J$

The work function of the aluminum metal is calculated as;

Ф = E - K.E

Ф = 8.02 x 10⁻¹⁹ - (0.92 x 1.602 x 10⁻¹⁹)

Ф = 8.02 x 10⁻¹⁹ J - 1.474 x 10⁻¹⁹ J

Ф = 6.546 x 10⁻¹⁹ J

The maximum wavelength of light that could liberate electrons from the aluminum metal is calculated as;

$\phi = hf = \frac{hc}{\lambda_{max}} \\\\\lambda_{max} = \frac{hc}{\phi} \\\\\lambda_{max} = \frac{(6.626\times 10^{-34}) \times (3 \times 10^8) }{6.546 \times 10^{-19}} \\\\\lambda_{max} = 3.037 \times 10^{-7} m\\\\\lambda_{max} = 303.7 \ nm$

3 0

3 years ago

Superman is standing 393 m horizontally away from Lois Lane. A villain drops a rock from 4.00 m directly above Lois. If Superman

Sergio039 [100]

Answer:

-963.93 m/s²

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

$s=ut+\frac{1}{2}at^2\\\Rightarrow 4=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{4\times 2}{9.81}}\\\Rightarrow t=0.903\ s$

$s=ut+\frac{1}{2}at^2\\\Rightarrow 393=0\times 0.0903+\frac{1}{2}\times a\times 0.903^2\\\Rightarrow a=\frac{393\times 2}{0.903^2}\\\Rightarrow a=963.93\ m/s^2$

The acceleration of Superman would be -963.93 m/s² from Lois' perspective

6 0

3 years ago

1. If the angle of the ramp were increased from 30˙ to 45˙, how would this change the weight of the box? Explain.

yawa3891 [41]

When the angle of the ramp increases, the weight of the box acting perpendicular to the ramp decreases.

<h3>Normal reaction of the box</h3>

The normal reaction of the box is due to weight of the box acting perpendicular to the ramp.

Fn = Wcosθ

<h3>when the angle of the ramp = 30⁰</h3>

Fn = Wcos(30)

Fn = 0.866W

<h3>when the angle of the ramp = 45⁰</h3>

Fn = W x cos(45)

Fn = 0.7071W

Thus, when the angle of the ramp increases, the weight of the box acting perpendicular to the ramp decreases.

Learn more about normal reaction here: brainly.com/question/18292235

#SPJ1

4 0

2 years ago