calculating light in physics

Answer:

When the temperature of the coffee is 50 °C, the time will be 20.68 mins

Explanation:

Given;

The initial temperature of the coffee T₀ = 95 °C

The temperature of the room = 21°C

Let T be the temperature at time of cooling t in mins

According to Newton's law of cooling;

[tex]\frac{dT}{dt} \alpha (T-21)\\\\\frac{dT}{dt} = k (T-21)\\\\\frac{dT}{T-21} = kdt\\\\\int\limits {\frac{dT}{T-21}} = \int\limits kdt\\\\Log(T-21) =kt + Logc \\\\Log (\frac{T-21}{c} ) = kt\\\\T -21 = ce^{kt}\\\\At \ t = 0, T = 95\\\\95-21 = ce^0\\\\74 = c\\\\New, equation: T -21 = 74e^{kt}\\\\Again; when \ t= 5\ min, T = 80\\\\80 -21 = 74e^{5k}\\\\59 = 74e^{5k}\\\\e^{5k} = \frac{59}{74}\\\\ 5k = ln(\frac{59}{74})\\\\5k = -0.2265\\\\k = -0.0453[/tex]

When the temperature is 50 °C, the time t in min is calculated as;

[tex]T -21 = 74e^{-0.0453t}\\\\50 -21 = 74e^{-0.0453t}\\\\29 = 74e^{-0.0453t}\\\\\frac{29}{74} = e^{-0.0453t}\\\\0.39189 = e^{-0.0453t}\\\\ln(0.39189 ) = {-0.0453t}\\\\-0.93677 = {-0.0453t}\\\\t = \frac{-0.93677}{-0.0453}\\\\ t = 20.68 \ mins[/tex]

Therefore, when the temperature of the coffee is 50 °C, the time will be 20.68 mins

In 10 minutes the hot coffee will attain the temperature of 50 degrees Celsius.

Initially the hot cup of coffee at the temperature of 95 degrees Celsius but after 5 minutes its temperature decreases from 95 to 85 degrees Celsius which is 15 degrees Celsius decrease so in other 5 minutes, the temperature decreases to 65 degrees Celsius.

Again after 5 minutes the temperature will further decrease finally the cup of coffee attain the temperature of 50 degrees Celsius so we can conclude that in 10 minutes the hot coffee will gain the 50 degrees Celsius temperature.

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Answer:

a. diamonds

Explanation:

solid is the matter that has definite shape and definite volume. One good example is a diamond because contains particles that are strongly attract to each other.

Answer:

A object having kinetic energy is in motion state.And the object whi posses potential energy i s in state of podition.

Answer:

Objects are relative to other moving and stationary objects.

Kinetic energy can be transferred from one moving object to another.

Potential energy is stored energy in an object.

Answer:

electrical energy transforming into sound energy in speaker

Answer:

the first one. Electrical energy transforming into sound energy in a speaker

Answer: It will be about 44.1m

Explanation:

Answer:

it will move in 356.5g in diagonal direction(resultant or between the both direction)

Explanation:

285+428/2=356.5g

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Answer:

Explanation:

If the ray were not deviated, it would travel straight through the mirror. Due to the mirror, the incident ray is reflected at 30°. The ray travels 30° + 30° = 60°. The angle of deviation is 180° - 60° = 120°.

Answer:

I think it will get colder

Explanation:

Answer:

The water molecules go faster as it gets colder they go slower

Explanation:

trust me thats the answer

Answer:

Divide by 1000

Explanation:

Answer:

d = 150 km

Explanation:

Speed of an airplane is 600 km/h

We need to find how far it travel in 1/4 hour.

We know that the speed of an object is given by distance travelled divided by the time taken. Let d is the distance covered in 1/4 hour. So,

[tex]v=\dfrac{d}{t}\\\\d=v\times t\\\\d=600\ km/h \times \dfrac{1}{4}\ h\\\\d=150\ km[/tex]

So, it will cover 150 km.

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

From the question

mass = 10 g

density = 87 g/ml

We have

[tex]volume = \frac{10}{87} \\ = 0.114942528...[/tex]

We have the final answer as

Hope this helps you

Answer:

I agree

Explanation:

I agree because most of the times girls pass more time with their mom since they hace more things in common, it’s the same with the boys.

Answer:

1 Newton

Explanation:

Mass of bowl (Mb) = 50 g = 0.05 kg

Initial Velocity (Vo) = 10 mL/s = 10g/s

time (t) = 5.0s

Mass of water (Mw) = 10 g/s * 5s = 50 g = 0.05 kg

*Vob = initial velocity of bowl

*Vow = initial velocity of water

*Vf = final velocity

*g = gravity = 9.8

Conservation of momentum [Inelastic Collision]:

Impulse-Momentum Theorem:

Scale Reading:

Answer:

1. 90N

2. 200N

3. 400N

4.20w

5.7200N

Explanation:

1.F=ma

30 * 3 = 90

2.W=FD

50 * 4=200

4. P=W/t

300/15=20

5.W= Pt. 2minutes = 120sec

60*120 = 7200

Answer:

Average acceleration is 2.5 m/s^2.

Explanation:

Average acceleration can be found by dividing the change in speed by the change in time.

We know that the initial velocity=10m/s, the final velocity=30m/s and time elapsed is t=8s.

a= (Final velocity-Initial Velocty)/t

a=(30-10)/8=20/8=2.5 m/s^2

Answer:

It is independent of the path of the body and depends only on the starting and ending points.

Explanation:

In Physics we define a conservative force as a force that is independent of the path of the body and depends only on the starting and ending points.

For conservative forces we can write;

KEi + PEi = KEf +PEf

where;

KEi= initial kinetic energy

PEi= initial potential energy

KEf= final kinetic energy

PEf= final potential energy

This equation is known as the principle conservation of mechanical energy . It applies only to conservative forces where friction is negligible. The term KE + PE  is also known as the total mechanical energy of the system.

Answer:

Gravity can affect the motion of objects as the force pulls objects closer to earth. Kinetic energy also causes movement in objects as that is energy in motion coming from stored energy known as (potential energy). With almost most importantly is needed is a force as without a force acting upon an objects is moving will continue to move and an object at rest will remain at rest as a gravitational pull or kinetic and potential energy for example are forces.

Explanation:

Have a great day :)

Answer:

0.65

Explanation:

For whatever reasons, the parameters are not giving. So, I will assume by myself to make the calculations easier. You can substitute whatever it is to it from your question.

Given that

Radius of the road, r = 63 m

Speed of the car, v = 20 m/s

The relationship between a car that is passing through a curve and it's frictional force is said to be

U(s) * g = v²/r

In the formula above,

U(s) = coefficient of static friction

g = acceleration due to gravity, 9.8 m/s²

v = velocity of the car

r = radius of the road

Now when we substitute the earlier stated values, we have

U(s) * 9.8 = 20² / 63

U(s) * 9.8 = 400 / 63

U(s) * 9.8 = 6.35

U(s) = 6.35 / 9.8

U(s) = 0.65

Thus, our coefficient of static friction, based on the stated values is 0.65

Answer:

  φ = B sin (2π n/a   x)

Explanation:

In quantum mechanics when a particle moves freely it implies that the potential is zero (V = 0), so its wave function is

     φ = A cos kx + B sin kx

we must place the boundary conditions to determine the value of the constants A and B.

In our case we are told that the particle cannot be outside the boundary given by x = ± a / 2

therefore we must make the cosine part zero, for this the constant A = 0, the wave function remains

    φ = B sin kx

the wave vector is

      k = 2π /λ

now let's adjust the period, in the border fi = 0 therefore the sine function must be zero

         φ (a /2) = 0

          0 = A sin (2π/λ  a/2)

therefore the sine argument is

          2π /λ   a/2 = n π

          λ= a / n

we substitute

          φ = B sin (2π n/a   x)

Answer:

adding bulbs:bulbs will glow in parallel circuit.

but the brightness of each bulb differs in series circuit.

removing bulbs:if u remove a bulb from parallel circuit,the other bulbs continue glowing in the same brightness

but if u remove a bulb in series circuit,the brightness of each bulb increases.

Answer:

The person above is correct.

Explanation:

In a parallel sequence, the light bulbs have electrons that flow equally. Though, in a series circuit, it's mainly connected to one wire, and the electrons get weaker.

Answer:

1.66m

Explanation:

Using the conservation law

PE = KE

mgh = 1/2mv²

gh = V²/2

g is the acceleration due to gravity = 9.81m/s²

h is the height of the hill

V is the velocity = 5.71m/s

Substitute

9.81h = 5.71²/2

Cross multiply

2×9.81h = 5.71²

19.62h = 32.6041

h = 32.6041/19.62

h = 1.66m

Hence the height of the hill is 1.66m

Answer:

Explanation:

graphing is helpful

helps visualize the line

of your equation

Answer:

Platelets

Explanation:

Platelets are tiny blood cells that help your body form clots to stop bleeding. If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a clot to stop the bleeding.

Answer:

[tex]\boxed {\tt Platelets}[/tex]

Explanation:

There are three main types of blood cells:

We are looking for which blood cell helps clot the blood. From the list above, we can see the best answer is platelets.

Answer:

(a) The work done by the gas on the surroundings is, 17537.016 J

(b) The entropy change of the gas is, 73.0709 J/K

(c) The entropy change of the gas is equal to zero.

Explanation:

(a) The expression used for work done in reversible isothermal expansion will be,

where,

w = work done = ?

n = number of moles of gas  = 4 mole

R = gas constant = 8.314 J/mole K

T = temperature of gas  = 240 K

= initial volume of gas  =  

= final volume of gas  =  

Now put all the given values in the above formula, we get:

The work done by the gas on the surroundings is, 17537.016 J

(b) Now we have to calculate the entropy change of the gas.

As per first law of thermodynamic,

where,

= internal energy

q = heat

w = work done

As we know that, the term internal energy is the depend on the temperature and the process is isothermal that means at constant temperature.

So, at constant temperature the internal energy is equal to zero.

Thus, w = q = 17537.016 J

Formula used for entropy change:

The entropy change of the gas is, 73.0709 J/K

(c) Now we have to calculate the entropy change of the gas when the expansion is reversible and adiabatic instead of isothermal.

As we know that, in adiabatic process there is no heat exchange between the system and surroundings. That means, q = constant = 0

So, from this we conclude that the entropy change of the gas must also be equal to zero.

Explanation:

Answer:

The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.

Explanation:  

The energy (E) of a photon is:

[tex] E = h\frac{c}{\lambda} [/tex]

Where:

h: is the Planck's constant = 6.62x10⁻³⁴ J.s

λ: is the wavelength of the radiation = 8.97 cm

c: is the speed of light = 3.00x10⁸ m/s

[tex] E = h\frac{c}{\lambda} = 6.62 \cdot 10^{-34} J.s\frac{3.00\cdot 10^{8} m/s}{8.97 \cdot 10^{-2} m} = 2.21 \cdot 10^{-24} J [/tex]

Hence, the energy of one photon is 2.21x10⁻²⁴ J.

Now, if we multiply the answer by 10²⁵ we have:

[tex] E = 2.21 \cdot 10^{-24} J \cdot 10^{25} = 22.10 J [/tex]

I hope it helps you!

The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.

We know that

[tex]E = h\frac{c}{\lambda}[/tex]

Here

h be the Planck's constant = 6.62x10⁻³⁴ J.s

λ be the wavelength of the radiation = 8.97 cm

c be the speed of light = 3.00x10⁸ m/s

Now

Here we need to multiply the answer 10^25 so that the correct answer could come.

[tex]E = 6.62.10^{-34} \frac{3.00.10^{8}}{8.97.10^{-2}}[/tex]

=  2.21x10⁻²⁴ J.

= 22.10 J.

Hence, the energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.

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Answer:

the Kinetic energy of the ball also increases.

the potential energy of the ball also increases.

mechanical energy of ball remains same.

Explanation:

KINETIC ENERGY:

The kinetic energy of the object depends upon the velocity of the object. As the formula suggests:

K.E = (1/2)mv²

As, the ball is falling down, it accelerates with a value equal to acceleration due to gravity. Thus, the speed increases as the ball falls.

Therefore, the Kinetic energy of the ball also increases.

POTENTIAL ENERGY:

Th potential energy of an object depends upon its height. As, the formula suggests:

P.E = mgh

As, the ball falls, its height decreases.

Therefore, the potential energy of the ball also increases.

MECHANICAL ENERGY:

Mechanical energy is the sum of kinetic energy and potential energy. According to law of conservation of energy, the total energy of the system always remains constant. It may change the forms but the total energy remains same. Thus, in this case potential energy is converted to kinetic energy.

Therefore, mechanical energy of ball remains same.

Answer:

Explanation:

The question is incomplete. Here is the complete question with attachment below.

In the above figure on the LEFT side, a block (mass = 2.8 kg) starts from rest at the top of a frictionless inline and slides to the bottom. The height of the incline is h=6.5 m, angle

Answer:

Dividing the silicon density by 1000 and then multiply it by 1000000.

Explanation:

A kilogram equals 1000 grams and a cubic meter equals 1000000 cubic centimeters. Hence, we must divide the silicon density by 1000 and then multiply itby 1000000 to convert the value into kilograms per cubic centimeter. That is:

[tex]x = 2.33\,\frac{g}{cm^{3}}\times \frac{1\,kg}{1000\,g}\times \frac{1000000\,cm^{3}}{1\,m^{3}}[/tex]

[tex]x = 2330\,\frac{kg}{m^{3}}[/tex]

In a nutshell, we must multiply the density of silicon by 1000 to obtains its value in kilograms per cubic meter.