1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ohaa [14]
3 years ago
5

¿Qué resistencia debe ser conectada en paralelo con una de 20 Ω para hacer una

Physics
1 answer:
Lisa [10]3 years ago
6 0

Answer:

La resistencia que debe ser conectada en paralelo con una de 20 Ω para hacer una  resistencia combinada de 15 Ω tiene un valor de 60 Ω

Explanation:

Las resistencias son aquellos dispositivos en los circuitos eléctricos que suelen emplearse para oponerse al paso de la corriente eléctrica.

Se denomina resistencia resultante o equivalente al valor de la resistencia que se obtiene al considerar un conjunto de ellas.

Cuando tenes resistencias en paralelo la corriente se divide y circula por varios caminos.

La resistencia equivalente de un circuito de resistencias en paralelo es igual al recíproco de la suma de los inversos de las resistencias individuales:

R=\frac{1}{\frac{1}{R_{1} } +\frac{1}{R_{2} } +...+\frac{1}{R_{N} }}

Esto también puede ser expresado como:

\frac{1}{R} =\frac{1}{R_{1} } +\frac{1}{R_{2} } +...+\frac{1}{R_{N} }

Entonces, en este caso sabes:

  • R= 15 Ω
  • R1= 20 Ω
  • R2=?

Reemplazando:

\frac{1}{15} =\frac{1}{20}+\frac{1}{R2}

y resolviendo:

\frac{1}{R2} =\frac{1}{15} -\frac{1}{20}

\frac{1}{R2} =\frac{1}{60}

se obtiene:

R2=60 Ω

<u><em>La resistencia que debe ser conectada en paralelo con una de 20 Ω para hacer una  resistencia combinada de 15 Ω tiene un valor de 60 Ω</em></u>

You might be interested in
Mass is the amount of matter in an object what describes the amount of space the object takes up?
saveliy_v [14]
C volume because the volume take up the Mater and space around it thing
6 0
1 year ago
Where is a trench most likely to occur?
Dafna1 [17]
D. convergent plate boundary involving an oceanic plate
7 0
3 years ago
Read 2 more answers
A property unique to a conducting substance that determines its resistance is called:
elena-s [515]

Answer:

B. Resistivity

Explanation:

Resistance offered by a substance of unit area per unit length.

6 0
3 years ago
Gravitational notes of physics ​
Pachacha [2.7K]

Answer:

Every object in the universe attracts other object by a force of attraction, called gravitation, which is directly proportional to the product of masses of the objects and inversely proportional to the square of distance between them. This is called Law of Gravitation or Universal Law of Gravitation.

Let masses (M) and (m) of two objects are distance (d) apart. Let F be the attractional force between two masses.

Importance of The Universal Law of Gravitation

It binds us to the earth.

It is responsible for the motion of the moon around the earth.

It is responsible for the motion of planets around the Sun.

Gravitational force of moon causes tides in seas on earth.

Free Fall

When an object falls from any height under the influence of gravitational force only, it is known as free fall.

Acceleration Due to Gravity

When an object falls towards the earth there is a change in its acceleration due to the gravitational force of the earth. So this acceleration is called acceleration due to gravity.

The acceleration due to gravity is denoted by g.

The unit of g is same as the unit of acceleration, i.e., ms−2

Mathematical Expression for g

From the second law of motion, force is the product of mass and acceleration.

F = ma

For free fall, acceleration is replaced by acceleration due to gravity.

Therefore, force becomes:

F = mg ….(i)

But from Universal Law of Gravitation,

Factors Affecting the Value of g

As the radius of the earth increases from the poles to the equator, the value of g becomes greater at the poles than at the equator.

As we go at large heights, value of g decreases.

To Calculate the Value of g

Value of universal gravitational constant, G = 6.7 × 10–11 N m2/ kg2,

Mass of the earth, M = 6 × 1024 kg, and

Radius of the earth, R = 6.4 × 106 m

Putting all these values in equation (iii), we get:

Thus, the value of acceleration due to gravity of the earth, g = 9.8 m/s2.

Difference between Gravitation Constant (G) and Gravitational Acceleration (g)

S. No.

Gravitation Constant (G)

Gravitational acceleration (g)

1.

Its value is 6.67×10-11Nm2/kg2.

Its value is 9.8 m/s2.

2.

It is a scalar quantity.

It is a vactor quantity.

3.

Its value remains constant always and everywhere.

Its value varies at various places.

4.

Its unit is Nm2/kg2.

Its unit is m/s2.

Motion of Objects Under the Influence of Gravitational Force of the Earth

Let an object is falling towards earth with initial velocity u. Let its velocity, under the effect of gravitational acceleration g, changes to v after covering the height h in time t.

Then the three equations of motion can be represented as:

Velocity (v) after t seconds, v = u + ght

Height covered in t seconds, h = ut + ½gt2

Relation between v and u excluding t, v2 = u2 + 2gh

The value of g is taken as positive in case of the object is moving towards earth and taken as negative in case of the object is thrown in opposite direction of the earth.

Mass & weight

Mass (m)

The mass of a body is the quantity of matter contained in it.

Mass is a scalar quantity which has only magnitude but no direction.

Mass of a body always remains constant and does not change from place to place.

SI unit of mass is kilogram (kg).

Mass of a body can never be zero.

Weight (W)

The force with which an object is attracted towards the centre of the earth, is called the weight of the object.

Now, Force = m × a

But in case of earth, a = g

∴ F = m × g

But the force of attraction of earth on an object is called its weight (W).

∴ W = mg

As weight always acts vertically downwards, therefore, weight has both magnitude and direction and thus it is a vector quantity.

The weight of a body changes from place to place, depending on mass of object.

The SI unit of weight is Newton.

Weight of the object becomes zero if g is zero.

Weight of an Object on the Surface of Moon

Mass of an object is same on earth as well as on moon. But weight is different.

Weight of an object is given as,

Hence, weight of the object on the moon = (1/6) × its weight on the earth.

Try the following questions:

Q1. State the universal law of gravitation.

Q2. When we move from the poles to the equator, the value of g decreases. Why?

Q3. If two stones of 150 gm and 500 gm are dropped from a height, which stone will reach the surface of the earth first and why ?

Q4. Differentiate between weight and mass.

Q5. Why is the weight of an object on the moon 1/6th its weight on the earth??

7 0
3 years ago
If you saw a waxing gibbous moon what phase would you expect one week later?
Leona [35]
Seven days after a waxing gibbous moon, the moon will be waning gibbous, and at some point during that seven days, it will have been Full.
6 0
3 years ago
Other questions:
  • Select all of the answers that apply.
    11·2 answers
  • Volume of an block is 5 cm3. If the density of the block is 250 g/cm3, what is the mass of the block ?​
    12·1 answer
  • What was the significance of the double-slit experiment? A. It showed that light had wave properties. B. It first demonstrated t
    8·1 answer
  • As a car skids to a stop, friction transforms kinetic energy to
    14·1 answer
  • PLEAASE HELP KE WITH THESE THREE YOULL GET POINTS
    6·1 answer
  • What does kevlar mean??
    8·1 answer
  • Which of these is exhibiting kinetic energy? Which of these is exhibiting kinetic energy? the high-energy phosphate bonds of a m
    7·1 answer
  • The 2nd maximum of a double slit diffraction pattern makes an angle 20 degrees when a wavelength of 600 nm is used. What is the
    10·1 answer
  • PLEASE HELP THIS IS A 53 QUESTION TEST
    13·1 answer
  • Which of these galaxies is most likely to be oldest?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!