please help me out i'm so depressed and such a failure
how does the brightness of the lamp (L) vary if we dispalce the cursor (C) of the rheostat
a)Towards A
b) Towards B​

Answer:

I can't see option dear

Explanation:

Answer:

ok so first ur not a failure and its okay don't be so hard on ur self

Answer:

Part A

The sound intensity at the location 150 from the firework = 4.3[tex]\overline 5[/tex] W/m²

Part B

The power the firework is emitting is approximately 1,231.5 kW

Explanation:

Part A

The data of the firework sound heard by the two friends are;

Let 'A' represent the location of the friend at a point 150 m from the fireworks and let 'B' represent the location of the friend watching from a distance of 700 m from the firework

The distance of 'A' from the sound, r₁ = 150 m

The distance of 'B' from the sound, r₂ = 700 m

The intensity at which 'B' hears the sound, I₂ = 0.2 W/m²

The relationship between sound intensity and distance is given as follows;

[tex]\dfrac{I_2}{I_1} = \left (\dfrac{r_1}{r_2} \right )^2[/tex]

[tex]\therefore {I_1} = \dfrac{I_2}{ \left (\dfrac{r_1}{r_2} \right )^2} = I_2 \times \left (\dfrac{r_2}{r_1} \right )^2[/tex]

Plugging in the values gives;

[tex]\therefore {I_1} = 0.2 \times \left (\dfrac{700}{150} \right )^2 = \dfrac{196}{45} = 4.3\overline 5[/tex]

The sound intensity at location 'A', I₁ = 4.3[tex]\overline 5[/tex] W/m²

Part B

The relationship between power, 'P', and intensity, 'I', is presented as follows;

[tex]I = \dfrac{P}{4 \cdot \pi \cdot r^2}[/tex]

P = I·4·π·r² = 4·I·π·r²

Therefore, at point 'A', where the distance, r₁ = 150 m, and the intensity, I₁ = 4.3[tex]\overline 5[/tex] W/m², we have;

P = 4 × 4.3[tex]\overline 5[/tex] W/m² × π × (150 m)² = 1231504.32021 W

The power the firework is emitting, P ≈ 1,231.5 kW.

Answer:

             air       water      iron        helium

v(m/s)   280     2200      17780     39682

Explanation:

The speed of a wave depends on the physical properties of the medium where it travels, in the case of a longitudinal wave such as sound, it depends on the resistance to deformation (volume modulus and the density of the medium

         v = [tex]\sqrt{ \frac{B}{ \rho } }[/tex]

in the mentioned materials they are constant  

             air       water      iron        helium

B           1 10⁵    2.2 10⁹    140 10⁹   0.05 10⁹

ρ           1.28     997        7874       1.26

v(m/s)   280     2200      17780     39682

Answer:

=> Rheostat is an electric device used as a variable resistance, like the regulator of the fan. It is used to change the electric resistance in the electric circuit.

=> Rheostat works on the principle of Ohm’s law. Ohm’s law states that current in a circuit is inversely proportional to the resistance at the given temperature.

[tex] \infty \infty \infty [/tex]

Answer:

K.E = 400

Explanation:

Given the following data;

Mass = 0.02kg

Velocity = 200m/s

To find the kinetic energy;

Kinetic energy can be defined as an energy possessed by an object or body due to its motion.

Mathematically, kinetic energy is given by the formula;

[tex] K.E = \frac{1}{2}MV^{2}[/tex]

Where;

K.E represents kinetic energy measured in Joules.

M represents mass measured in kilograms.

V represents velocity measured in metres per seconds square.

Substituting into the formula, we have;

[tex] K.E = \frac{1}{2}*0.02*200^{2}[/tex]

[tex] K.E = \frac{1}{2}*0.02*40000 [/tex]

[tex] K.E = 0.02*20000 [/tex]

K.E = 400

Answer:

Sunlight allows plants to perform photosynthesis, a process which is required for plant growth and health. ... Plants that are denied sufficient light will eventually lose their color and die. Plants deprived of light will grow upward, stretching their stems more rapidly that usual, searching for light.

Answer:

Sunlight allows plants to perform photosynthesis, a process which is required for plant growth and health. ... Plants that are denied sufficient light will eventually lose their color and die. Plants deprived of light will grow upward, stretching their stems more rapidly that usual, searching for light

Explanation:

i got this from  

https://sciencing.com/what-happens-to-plants-if-they-have-no-sun-12486997.html#:~:text=Sunlight%20allows%20plants%20to%20perform,for%20plant%20growth%20and%20health.&text=Plants%20that%20are%20denied%20sufficient,that%20usual%2C%20searching%20for%20light.

Answer:

If I was the white mouse, I would either find somewhere to hide that matches my fur color to camoflouge with or dig into the dirt so less visible.

To find white colour habitat.

If I was the white mouse, I would find white colour place for living because in that white colour the predators can't see me and i will be safe from them so we can conclude that finding white colour habitat is the best choice to safe myself.

Learn more about survive here: https://brainly.com/question/24323334

Answer:

(a) h = 1.5 m (b) v = 5.29 m/s

Explanation:

1. Given that,

Mass of a rollercoaster cart, m = 4500 kg

It has 67,500 J of gravitational potential  energy.

We know that, the gravitational potential  energy is given by :

[tex]E=mgh[/tex]

Put all the values,

[tex]h=\dfrac{E}{mg}\\\\h=\dfrac{67500}{4500\times 10}\\\\h=1.5\ m[/tex]

2. The kinetic energy of an object is given by :

[tex]E=\dfrac{1}{2}mv^2\\\\v=\sqrt{\dfrac{2E}{m}}\\\\v=\sqrt{\dfrac{2\times 63000}{4500}}\\\\v=5.29\ m/s[/tex]

Hence, this is the required solution.

Explanation:

Momentum of an object is defined as the product of the mass of object and the velocity with which it is moving.

p = mv

where, p = momentum, m= mass and v= velocity

mass m = 0.7 Kg and v = 20 m/s

p = 0.7×20 = 14 Kg-m/sec

Therefore, momentum of the object  = 14 kg-m

Answer:

1) 15.6

2) 2.03

Explanation:

The power output of the electric toaster, P = 2,400 W

The voltage rating of the power outlet, V = 120 V

The number of hours the toaster is used during a month = 6.5 hours

1) Electrical energy, E = Electrical power, P × Time, t

The electrical energy dissipated by the toaster, 'E', is given as follows;

E = 2,400 W × 6.5 hrs = 15,600 Wh = 15.6 kWh

The electrical energy dissipated by the toaster, during the measured month in kWh, E = 15.6

2) Let 'C' represent the monthly cost of toaster and let 'B' represent the amount charged by the local power company, we have;

The charges for (electrical) power by the local power company, B = $0.13/kWh

The monthly cost of the toaster, C = E × B

∴ C = 15.6 kWh × $0.13/kWh = $2.028

By rounding off to 2 decimals, the monthly cost of the toaster (in $), C ≈ 2.03.

Answer:

[tex]L=11.3\ kg-m^2/s[/tex]

Explanation:

Given that,

Angular speed of a skater, [tex]\omega=3\ rot/s=18.84\ rad/s[/tex]

The moment of inertia of the skater, I = 0.6 kg-m²

We need to find the angular momentum of the skater. The formula for the angular momentum of the skater is given by :

[tex]L=I\omega[/tex]

Substitute all the values,

[tex]L=0.6\times 18.84\\\\L=11.3\ kg-m^2/s[/tex]

So, its angular momentum is equal to [tex]11.3\ kg-m^2/s[/tex].

Answer: Hello Results of examples 5.4 and 5.5 are missing from your question but I was able to find it online and use it to resolve your question

answer :

a) 1780 m^3/sec

b)  23.81 m

Explanation:

a) calculate the number of m^3 of water flowing through an OTEC plant charge

assumption : assuming an ideal heat engine

 Q / t   =  m*c*∆T * (eff) / t

1e^9 J/s = 1g/cc *V(1cal/g°C) * 2°C (6.7%)*(4.184J/cal) / t

Hence:  V / t ( number of m^3 of water ) = 1.78e^9 cc / sec = 1.78 * 10

= 1780 m^3/sec

b) Determine the diameter of pipes

Given that the water flows at  4m/s  ( velocity )

1780 m^3 /sec = A * V  ------ ( 1 )

A = π*d^2/4 =  1780 / 4 = 445 m^2  -------- ( 2 )

v = 4 m/s

Back to equation 2

d^2 = ( 445 * 4 ) / π

      ≈ 567

∴ necessary diameter ( d ) = [tex]\sqrt{567}[/tex] = 23.81 m

Answer:

It is most likely option A B and C

Answer:

I think option A ,B,D are correct

Answer:

C

Explanation:

Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces

I hope this helps a little bit

The correct Option is :

=》(C) The square of the distance that separates them

where,

f = gravitational force

r = distance between the objects

Answer:

FALSE

Explanation:

You breath in oxygen and your blood takes it through your body then you breath it out as carbon dioxide

Answer:

infinity

Explanation:

this is because time is irrelevant

Answer:

In coastal areas, strong winds and powerful waves break off soft or grainy rocks from hardier rocks. Too much weathering occurs, it might break off parts of the cliff and be dangerous to humans, or animals.

Rain has acid in it which could eat up the cliff.

Explanation:

Answer:I think it’s convection

Explanation:

Answer:

the anser is B

Explanation:

Answer:

1/2 m u^2     initial Kinetic Energy of body

m g h        Potential Energy body attains as it rises to height

1/2 m u^2 = m g h      conversion of KE to PE

h = u^2 / ( 2  g)

Answer:

Explanation:

I just did the Gizmo and the correct answer is 12 :) Hope this helps!

The total resistance of the circuit for parallel resistors of 41 Ω and 17 Ω is 12Ω. Hence option D is correct.

When two or more resistors are connected between two same points, they are said to be connected in parallel combination(as shown in fig).  The equivalent resistance is the reciprocal and the sum of reciprocals of all resistance connected in parallel combination.

[tex]\frac{1}{R_{s}} = \frac{1}{R_{1}} + \frac{1}{R_{2} } + \frac{1}{R_{3}} ..........+ \frac{1}{R_{n} }[/tex]  where Rs is the equivalent or total resistance of the circuit.

In parallel combination, same potential difference exists across each resistor. But current through each resistance is different.

When two or more resistors are connected one after other, they are said to be connected in series as shown in figure. in this combination voltage difference across each resistance is different which is given by ohms law. current flowing through each resistance is same.

equivalent resistance for series combination is given by,

R(s) = R₁ + R₂ + R₃...........+R(n).

In this problem given resistance are not seen, Resistor can be with 41 and 17Ω.

Given,

R₁ = 17 Ω

R₂ = 41 Ω

[tex]R_{s} = ?[/tex]

by parallel combination,

[tex]\frac{1}{R_{s}} = \frac{1}{R_{1} } + \frac{1}{R_{2} }[/tex]

[tex]R_{s} = \frac{R_{1} R_{2} }{R_{1} + R_{2} }= \frac{17*41}{17+41} = \frac{697}{58} = 12[/tex]

R = 12 Ω.

Hence option D is correct.

To know more about Resistor :

https://brainly.com/question/24297401

#SPJ3.

Answer:

Nuclear power plants are fueled by uranium, which emits radioactive substances. Most of these substances are trapped in uranium fuel pellets or in sealed metal fuel rods. However, small amounts of these radioactive substances (mostly gases) become mixed with the water that is used to cool the reactor.

Answer:

10.1 m/s

Explanation:

Let the coordinates of the pelican's position be (x, y).

Now, since it is dropped from a height of 12.3 m, then initial velocity is zero and using Newton's 2nd law of motion, we have;

12.3 = 0 - ½gt²

½gt² = 12.3

t² = 12.3 × 2/9.8

t² = 2.51

t = √2.51

t = 1.5843 s

Now, it travels 16.0m horizontally before it hits the water below. Using the formula, distance = speed × time, we have;

16 = v_x•t

Thus;

16 = v_x × 1.5843

v_x = 16/1.5843

v_x = 10.1 m/s

Now, the velocity in the vertical y-direction is zero.

Thus;

v = √((v_x)² + (v_y)²)

v = √((10.1² + 0²))

v = 10.1 m/s

Answer: James headache will subside first

Explanation: powder medicines usually get absorbed faster therefore having a quicker effect

Answer:

That is because we apply less Work.

Brainliest?? I hope this helps!!!

Explanation:

Answer:

north pole of a magnet repels the north pole of another magnet no matter of their shape , size , weakness , strength ,etc .

Explanation: