An object that gives off electromagnetic waves based on its temperature
demonstrates which phenomenon?
A. Emission spectra
B. Blackbody radiation
C. Quantum mechanics
D. Photoelectric effect

Answer:

460.52 s

Explanation:

Since the instantaneous rate of change of the voltage is proportional to the voltage in the condenser, we have that

dV/dt ∝ V

dV/dt = kV

separating the variables, we have

dV/V = kdt

integrating both sides, we have

∫dV/V = ∫kdt

㏑(V/V₀) = kt

V/V₀ = [tex]e^{kt}[/tex]

Since the instantaneous rate of change of the voltage is -0.01 of the voltage dV/dt = -0.01V

Since dV/dt = kV

-0.01V = kV

k = -0.01

So, V/V₀ = [tex]e^{-0.01t}[/tex]

V = V₀[tex]e^{-0.01t}[/tex]

Given that the voltage decreases by 90 %, we have that the remaining voltage (100 % - 90%)V₀ = 10%V₀ = 0.1V₀

So, V = 0.1V₀

Thus

V = V₀[tex]e^{-0.01t}[/tex]

0.1V₀ = V₀[tex]e^{-0.01t}[/tex]

0.1V₀/V₀ = [tex]e^{-0.01t}[/tex]

0.1 = [tex]e^{-0.01t}[/tex]

to find the time, t it takes the voltage to decrease by 90%, we taking natural logarithm of both sides, we have

㏑(0.01) = -0.01t

So, t = ㏑(0.01)/-0.01

t = -4.6052/-0.01

t = 460.52 s

Answer:

[tex]d =3.7*10^{-3} m[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=1.2kg[/tex]

Spring constant [tex]\mu=22Nm^{-1}[/tex]

Amplitude [tex]A=5cm=0.05m[/tex]

Generally the equation for displacement d is mathematically given by

 [tex]d = Asin(\omega t)[/tex]

Where

 [tex]\omega=angular\ velocity[/tex]

 [tex]\omega=\sqrt{k/m}[/tex]

 [tex]\omega=\sqrt{22/1.2}[/tex]

 [tex]\omega=4.2817rads^{-1}[/tex]

Therefore  

 [tex]d = 0.05*sin(4.2817*1)[/tex]  

 [tex]d =3.7*10^{-3} m[/tex]

Answer: 4

Explanation:

MA = output force / input force

MA = 20 / 5

MA = 4

Hope this helps.  Please mark brainliest.

Answer:

There are a couple of interesting things about kinetic energy that we can see from the equation.

Kinetic energy depends on the velocity of the object squared. This means that when the velocity of an object doubles, its kinetic energy quadruples. A car traveling at 60 mph has four times the kinetic energy of an identical car traveling at 30 mph, and hence the potential for four times more death and destruction in the event of a crash.

Kinetic energy must always be either zero or a positive value. While velocity can have a positive or negative value, velocity squared is always positive.

Kinetic energy is not a vector. So a tennis ball thrown to the right with a velocity of 5 m/s, has the exact same kinetic energy as a tennis ball thrown down with a velocity of 5 m

Answer:

Explanation:

Reverse the second equation, and change the sign of the enthalpy

Answer:

friction is motion heat that collect hot vibration

Answer:

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Explanation:

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Answer:

[tex]I_2=0.50 w/m^2[/tex]

Explanation:

From the question we are told that:

initial Intensity [tex]I_1=0.020 w/m^2[/tex]

Final Electric field [tex]E_2=5E[/tex]

Generally the equation for Relation ship between intensity and Electric field is mathematically given by

 [tex]\frac{I_1}{I_2}= \frac{E_1^2}{E_2^2}[/tex]

Therefore

 [tex]I_2=\frac{I_1}{ \frac{E_1^2}{E_2^2}}[/tex]

 [tex]I_2=\frac{0.020}{ \frac{E^2}{5E^2}}[/tex]

 [tex]I_2=0.50 w/m^2[/tex]

Answer:

Explanation:

Given that:

mass = 10kg

damping constant C = 15 kg/s

length = 2 m

Force F = 6N

Using the Hooke's law:

F = kx

6 = 15x

k = 6 N /2 m

spring constant k = 3 N/m

For the critical damping

C² - 4k*m= 0

m = C²/4k

m = (15)²/4(3) kg

m = 225/12 kg

m = 18.75 kg

Answer:

B- the melting of polar ice caps

Explanation:

As the world's temperature increases, polar ice caps will no longer be able to remain solid.

Answer:

Tx not but mybe

Explanation:

for that reason its just trying to help

Answer:

The glass rod remains charged due to electrification by the silk

Answer:

Because molecules are to small for us people to see with the bare eye, unless you use a telescope.

Explanation:

Explanation:

Because in solid form, the molecules stood in place, not moving. In liquid state, the molecules move slowly but not as fast as air molecules.

Answer:

electromagnetism....

This question is incomplete, the complete question is;

In June 1985, a laser beam was sent out from the Air Force Optical Station on Maui and reflected back from the shuttle Discovery as it passed by 354 km overhead. The diameter of the central maximum of the beam at the shuttle position was said to be 9.1 m, and the beam wavelength was 500 nm.

What is the effective diameter of the circular laser aperture at the Maui ground station

Answer:

the effective diameter of the circular laser aperture at the Maui ground station is 4.747 cm

Explanation:

Given the data in the question;

Separation between observer and point L = 354 km = 354000 m

Linear separation D = 9.1 m

wavelength λ = 500 nm = 500 × 10⁻⁹ m

Now, for small angles;

θ = D / L

θ = 9.1 m /  354000 m

θ = 2.57 × 10⁻⁵ rad

For a circular aperture;

sinθ = ( 1.22 × λ ) / d

for small angles;

θ = ( 1.22 × λ ) / d

so

θ = 2 × θ

θ = 2 × [( 1.22 × λ ) / d]

we substitute

2.57 × 10⁻⁵ = 2 × [( 1.22 × 500 × 10⁻⁹ ) / d]

2.57 × 10⁻⁵ = 0.00000122 / d

d = 0.00000122 / 2.57 × 10⁻⁵

d = 0.04747 m

d = ( 0.04747 × 100 )m

d = 4.747 cm

Therefore, the effective diameter of the circular laser aperture at the Maui ground station is 4.747 cm

Answer:

F₂ = -7.3 N

Explanation:

Given that,

The mass of an object, m₁ = 3.7 kg

First force, F₁ = 11 N

The net acceleration of the object is 1 m/s².

We know that,

F₁+F₂ = ma

11+F₂ = (3.7)(1)

F₂ = 3.7-11

F₂ = -7.3 N

so, the other force is 7.3 N and it is acting in west direction.

Answer:

ans: 2250 meters

Explanation:

initial velocity (U)= 15 m/s

final velocity (V) = 0m/s , since need to come in rest

total time taken (T) = 5 min= 300 seconds

total distance covered (S)= UT + 1/2 aT^2 ,

a= acceleration

S= 15 × 300 + 0.5 ×(0 - 15) × 300

since a = (V - U)/ T

S = 4500 - 2250

S= 2250 m

According to Coulomb's law, rank the interactions between charged particles from highest potential energy to lowest potential energy.

Highest potential energy to lowest potential energy.

b. 1+ charge and 1+ charge seperated by 100 pm

a. 1+ charge and 1- charge seperated by 200 pm

c. 1+ charge and 1- charge seperated by 100 pm

d. 2+ charge and 1- charge seperated by 100 pm

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Answer:

We want to solve the sum:

6.74*10⁴ + 8.95*10⁴

first, we take the common factor 10⁴ out, so we get:

(6.74 + 8.95)*10⁴

Now we solve the sum:

(15.66)*10⁴

Now we want to rewrite it in exponential form, wo we can rewrite it as:

(15.66)*10⁴ = (1.566*10)*10⁴ = (1.566)*10*10⁴ = (1.566)*10⁴⁺¹ = 1.566*10⁵

k = 5.

what? Is there a picture you can show us with this question

Answer:

a) the required time is 0.6283 μs

b) the inductor current is 0.5 mA

Explanation:

Given the data in the question;

The capacitor voltage has its maximum value of 25 V at t = 0

i.e V[tex]_m[/tex] = V₀ = 25 V

we determine the angular velocity;

ω = 1 / √( LC )

ω = 1 / √( ( 20 × 10⁻³ H ) × ( 8.0 × 10⁻¹² F) )

ω = 1 / √( 1.6 × 10⁻¹³  )

ω = 1 / 0.0000004

ω = 2.5 × 10⁶ s⁻¹

a) How much time does it take until the capacitor is fully discharged for the first time?

V[tex]_m[/tex] =  V₀sin( ωt )

we substitute

25V =  25V × sin( 2.5 × 10⁶ s⁻¹ × t )

25V =  25V × sin( 2.5 × 10⁶ s⁻¹ × t )

divide both sides by 25 V

sin( 2.5 × 10⁶ × t ) = 1

( 2.5 × 10⁶ × t ) = π/2

t = 1.570796 / (2.5 × 10⁶)

t = 0.6283 × 10⁻⁶ s

t = 0.6283 μs

Therefore, the required time is 0.6283 μs

b) What is the inductor current at that time?

[tex]I[/tex](t) = V₀√(C/L) sin(ωt)

{ sin(ωt) = 1 )

[tex]I[/tex](t) = V₀√(C/L)

we substitute

[tex]I[/tex](t) = 25V × √( ( 8.0 × 10⁻¹² F ) / ( 20 × 10⁻³ H ) )

[tex]I[/tex](t) = 25 × 0.00002

[tex]I[/tex](t) = 0.0005 A

[tex]I[/tex](t) = 0.5 mA

Therefore, the inductor current is 0.5 mA

The time taken for the capacitor to fully discharge is 6.28 x 10⁻⁷ s.

The current in the inductor at the given time is 0.0005 A.

The angular velocity of the circuit is calculated as follows;

[tex]\omega = \frac{1}{\sqrt{LC} } \\\\\omega = \frac{1}{\sqrt{20 \times 10^{-3} \times 8 \times 10^{-12} } } \\\\\omega = 2.5 \times 10^6 \ rad/s[/tex]

V = V₀(sinωt)

sinωt = V/V₀

sinωt = = 25/25

sin(ωt) = 1

ωt = sin⁻¹ (1)

ωt = π/2

2.5 x 10⁶ t = π/2

t = 1.57 / (2.5 × 10⁶)

t = 6.28 x 10⁻⁷ s

The current in the inductor at the given time is calculated as follows

[tex]I(t) = V_0 \sqrt{\frac{C}{L} } \\\\I = 25 \times \sqrt{\frac{8\times 10^{-12}}{20 \times 10^{-3}} } \\\\I = 0.0005 \ A[/tex]

Learn more about inductor current here: https://brainly.com/question/4425414

Answer:

[tex]f=1.57\times 10^9\ Hz[/tex]

Explanation:

Given that,

A system can detect objects as small as 19.1 cm i.e. 0.191 m. It is the wavelength.

We know that,

Frequency, [tex]f=\dfrac{c}{\lambda}[/tex]

So,

[tex]f=\dfrac{3\times 10^8}{0.191}\\\\=1.57\times 10^9\ Hz[/tex]

So, the frequency of such a system is equal to[tex]1.57\times 10^9\ Hz[/tex].

Answer:

The maximum speed is 18.86 m/s.

Explanation:

initial  radius, r = 150 m

maximum speed, v = 26.5 m/s

new radius, r' = 76 m

Let the new maximum speed is v'.

The formula of the maximum speed is

[tex]tan\theta = \frac{v^2}{rg}[/tex]

So,

[tex]\frac{v'^2}{v^2}=\frac{r'}{r}\\\\\frac{v'^2}{26.5\times 26.5}=\frac{76}{150}\\\\v=18.86 m/s[/tex]

Answer:

Current = dQ/dt

or I = dQ/dt

Where I represents current.

Which is the rate of flow of charge.

Q=4 + 2t + t²

dQ/dt = 2 + 2t --- This is the relation that gives the instantaneous current.

At time t=2sec

dQ/dt = I = 2 + 2t

= 2 + 2(2)

=2 + 4

= 6A.

Answer:

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Answer:

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Answer:

The advantages of Hovercraft:

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