A certain capacitor, in series with a resistor, is being charged. At the end of 25 ms its charge is half the final value. The time constant for the process is about:

Answers

Answer 1

Answer:

  τ = 36 10⁻³ s

Explanation:

The charge of a circuit Rc is given by the expression

          q = q₀ (1 - [tex]e^{-t/ \tau }[/tex])

          q / q₀ = 1 - e^{-t/  \tau }

in this exercise they indicate that

          q / q₀ = ½

for a time t = 25 10⁻³ s

we substitute

          ½ = 1 - [tex]e^{- 25 \ 10^{-3} / \tau}[/tex]

          e^{- 25 \ 10^{-3} /  \tau} =  1 -½

         - 25 10⁻³ /τ = ln 0.5

         -25 10⁻³ / ln 0.5 = τ

         τ = 36 10⁻³ s


Related Questions

Why does the soccer ball not increase in size when air is pumped into it?

Answers

Answer:

(I'm not 100% sure about this)

Maybe its because the soccer ball is faulty. Such troublemakers can include holes in the ball, preventing it from inflating.

The density of dry air at room temperature and atmospheric pressure Is 1.2 kg m-3. What volume would 6 kg of dry air occupy under these conditions?​

Answers

Answer:

V = 5 m³

Explanation:

The density of air, d = 1.2 kg/m³

Mass of the dry air, m = 6 kg

We need to find the volume o the gas. We know that, the density of an object is given by mass divided by its volume. So,

[tex]d=\dfrac{m}{V}\\\\V=\dfrac{m}{d}\\\\V=\dfrac{6}{1.2}\\\\V=5\ m^3[/tex]

So, the volume of the dry air is 5 m³.

Water is being heated on the stove at 90 ⁰C. What is this temperature on the Fahrenheit degrees?

Answers

Answer:

194 degrees farenheit! hot

Explanation:

(90°C × 9/5) + 32 = 194°F

Answer:

194

Explanation:

to get from celcius to Fahrenheit

multiply temperature by 2 and add 30

In a wire, when elongation is 4 cm energy stored is E. if it is stretched by 4 cm, then what amount of elastic potential energy will be stored in it?

Answers

Answer:

4E

Explanation:

The elastic potential energy of an elastic material (e.g a spring, a wire), is the energy stored when the material is stretched or compressed. It is given by

U = [tex]\frac{1}{2}kx^2[/tex]               --------------------(i)

Where;

U = potential energy stored

k = spring constant of the material

x = elongation (extension or compression of the material).

From the first statement;

when elongation (x) is 4cm, energy stored (U) is E

Substitute these values into equation (i) as follows;

E = [tex]\frac{1}{2}k(4)^2[/tex]

E = 8k

Make k subject of the formula    

k = [tex]\frac{E}{8}[/tex]   [measured in J/cm]

From the second statement;

It is stretched by 4cm.

This means that total elongation will be 4cm + 4cm = 8cm.

The potential energy stored will be found by substituting the value of x = 8cm and k = [tex]\frac{E}{8}[/tex] into equation (i) as follows;

U = [tex]\frac{1}{2}\frac{E}{8} (8)^2[/tex]  

U = [tex]\frac{1}{2}{8E}[/tex]

U = [tex]{4E}[/tex]

Therefore, the potential energy stored will now be 4 times the original one.

How much energy is transferred when the potential difference is 230 volts and the charge is 5 coulombs?

Answers

Answer:

1150J

Explanation:

Voltage = energy / charge

energy = Voltage * charge

energy = 230v * 5C = 1150J

What are the wavelengths of x-rays and gamma rays?
a.
x-rays - 3 pm to 20 nm
gamma rays- less than 3 pm
c.
x-rays - 3 mm
gamma rays- 20 to 50nm
b.
x-rays - 400nm
gamma rays- 700nm
d.
None of the above

Answers

Answer:

1. less. 2 greater. 3. the same. 8. An FM radio station broadcasts its signal at a fre​- ... wave 3. | 3x108 = 269.15x107). = 3.20m. 2. An electromagnetic AM-band radio wave could have Base your answers to questions 9 and 10 on the informa- ... X rays. -Microwaves. -Long

A piece of iron has a mass of 30 g and its volume is 6.2 cm3. What is its density?

Answers

Answer:

Density = 4.84 g/cm³

Explanation:

Given the following data;

Mass = 30 g

Volume = 6.2 cm³

To find the density of the piece of iron;

Density can be defined as mass all over the volume of an object.

Simply stated, density is mass per unit volume of an object.

Mathematically, density is given by the equation;

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

Substituting into the equation, we have;

[tex]Density = \frac{30}{6.2}[/tex]

Density = 4.84 g/cm³

Una mochila tiene una masa de 5.9 Kg y se mueve con una aceleración de: 0.53 m/ seg2. ¿ Cuál es la fuerza que debe aplicar ?.

Answers

Answer:

3,13 N

Explanation:

Del enunciado de la segunda ley del movimiento de Newton;

F = ma

Dónde;

F = Fuerza aplicada

m = masa del cuerpo

a = aceleración del cuerpo

Sustitución de valores;

F = 5,9 kg * 0,53 m / seg2 = 3,13 N

Por tanto, la fuerza aplicada es 3,13 N

Do only number 5 and thank

Answers

Answer:

Quantity of charge = 1800 Coulombs

Explanation:

Given the following data;

Current = 1 A

Time = 0.5 hours

Conversion:

1 hour = 60 * 60 = 3600 seconds

0.5 hour = 0.5 * 3600 = 1800 seconds

To find the charge passing through the wire;

Mathematically, the quantity of charge passing through a conductor is given by the formula;

Quantity of charge = current * time

Substituting into the formula, we have;

Quantity of charge = 1 * 1800

Quantity of charge = 1800 Coulombs

Based on the law of conservation of energy, how can we reasonably improve a machine’s ability to do work?

Answers

Answer:

We can reasonably improve a machines ability to do work by reducing the friction between the moving parts of machine.

Explanation:

According to the law of conservation of energy, the energy can neither be created nor destroyed.

Find the magnitude and angle of a vector given the components: Bx = 7, By=-5​

Answers

Answer:

[tex] |B| = \sqrt{ {B _{x} }^{2} + {B _{y} }^{2} } \\ = \sqrt{ {7}^{2} + {5}^{2} } \\ = \sqrt{74} \\ = 8.6[/tex]

[tex]let \: the \: angle \: be \: \theta \\ \tan(\theta) = \frac{B _{y} }{B _{x} } \\ \tan( \theta) = \frac{ - 5}{7} \\ \theta = { \tan }^{ - 1} ( \frac{ - 5}{7} ) \\ = 35.5 \degree[/tex]

A rocket of mass M when empty carries a mass M of fuel. The rocket and fuel travel at speed v.
The engine of the rocket is fired and all of the fuel is expelled. The speed of the rocket increases
to 2v.

What happens to the kinetic energy of the rocket?
A It doubles.
B It halves.
C It increases by a factor of four.
D It stays the same.

Answers

The kinetic energy of the rocket should be A. it doubles.

What is kinetic energy?

Kinetic energy represents the energy where an object or a particle should be the reason for its motion. It transfers energy than it should be done on an object by applying a net force, so the object speeds up and thereby gains kinetic energy. In the case when the speed increased to 2v so the kinetic energy should also doubles.

Learn more about speed here: https://brainly.com/question/17052831

What would be the weight (in Newtons) of a person with a mass of 80 kg on Earth, where the acceleration due to gravity is approximately 9.8 m/s/s? *
please help asap

Answers

Answer:

ml tayo 1v1 durugin kita

Explanation:

ano takot ml 1v1

(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg.

Answers

Complete question:

(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C

Answer:

The energy that must be supplied to boil the given mass of the water is 672,000 J

Explanation:

Given;

mass of water, m = 2 kg

heat of vaporization of water, L =  330 kJ/kg

initial temperature of water, t = 20 ⁰C

specific heat capacity of water, c = 4200 J/kg⁰C

Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;

Q = mc(100 - 20)

Q = 2 x 4200 x (80)  

Q = 672,000 J

Q = 672,000 J

Q = 672,000 J

Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J

1 Ten (10) ml aqueous solutions of drug A (10% w/v) and drug B (25% w/v) are stored in two identical test tubes under identical storage conditions at 37°C for 3 months. If both drugs degrade by first-order, which drug will retain the highest percentage of initial concentration?

Answers

Answer:

YOUR answer is given below:

Explanation:

Drug B will retain the highest percentage of initial concentration.

First order degradation means that both solution will degrade by same amount in same time because first order is directly proportional relationship between given both aqueous solution.

Given that Ten (10) ml aqueous solutions of drug A (10% w/v) and drug B (25% w/v) are stored in two identical test tubes.

Since, initially concentration of Drug B is more. Therefore, at all instant concentration of Drug will be highest.

Learn more:

brainly.com/question/17029235

Explain why magnetic damping might not be effective on an object made of several thin conducting layers separated by insulation.

Answers

Answer:

The eddy currents will be very small.

Explanation:

An object made of several thin conducting layers separated by insulation may not be affected by magnetic damping because the eddy current produced in each layer due to induction will be very small and the opposing magnetic flux produced by the eddy currents will be very small.

NEED ANSWER QUICK, WILL GIVE BRAINLIEST! How many nails do sapiens have?
A. 6
B. 10
C. 3
D. None

Answers

Answer:

nice calculations!

Explanation:

None of the above. Or is it regarding toe alone with finger nails?

Q= Which one of the following statement is incorrect?
A. When a switch is closed in a circuit, no current flows.
B. A switch is a device for turning on and off an electric current.
C. An electric current is a complete loop around which a current can flow.
D. An electric current is a flow of charge

Answers

Answer:

A.

Explanation:

I think it might be the big number A

A 15.0 kilogram cart initially traveling at 2.0 meters per second east accelerates uniformly at 0.75 meter per second squared east for 6.0
seconds. What is the speed of the cart at the end of this 6,0 second interval? Please include all work - including givens, formula, substitution,
and units for full credit. (2)

Answers

Answer:

Explanation:

Since this is not parabolic motion, it is one-dimensional motion. Very simple. What we are given is

mass: 15.0 kg

initial velocity: 2.0 m/s

acceleration: .75 m/s/s

time: 6.0 seconds

Since we are looking for final velocity, the equation we need for this is

v = v0 + at that says final velocity is equal to the initial velocity plus the acceleration of the object times how long it travels. We don't have a need for the mass here at all.

[tex]v=2.0\frac{m}{s}+.75\frac{m}{s^2}(6.0s)[/tex]

Notice that one of the seconds labels to the right of the plus sign cancel out, leaving us with like units...which we HAVE to have if we want to add.

Simplifying a bit gives us

v = 2.0 m/s + 4.5 m/s so

v = 6.5 m/s

(I have 2 questions which are very similar)
Which of the chemical reactions above stores energy?
A. Cellular respiration
B. Photosynthesis
C. Both cellular respiration and photosynthesis
D. Neither cellular respiration nor photosynthesis

15 Which of the chemical reactions above releases energy?
A. Cellular respiration
B. Photosynthesis
C. Both cellular respiration and photosynthesis
D. Neither cellular respiration nor photosynthesis
(help!!!) SCIENCE

Answers

Answer:

B

A

Explanation:

please mark as brainliest :)

[tex]\boxed{\color\red\huge\tt\bold\purple{Question}}[/tex]
Define Inertia.​

Answers

Answer:

Inertia : a property of matter by which it continue in its existing state of rest or uniform motion in a straight line, unless that state is changed by external force.

HOPE ITS HELPS!!

[tex]\boxed{\color{red}\huge\tt\bold\purple{Answer}}[/tex]

Inertia is the tendency of an object to continue in the state of rest or of uniform motion. The object resists any change in its state of motion or rest.

An athlete running the velocity 3m/s due east is confronted with two trade winds. One wind travelling at 10m/s in a direction north 65degrees east and another wind travelling at 8m/s in a direction south 70degrees east. Find the resultant velocity and direction of the athlete

Answers

Answer:

v = 10.09 m / s,   8.78 North of East

Explanation:

The easiest way to solve this exercise is to decompose the velocities into a coordinate system, where the x-axis coincides with the West-East direction and the y-axis coincides with the South-North direction.

athlete's velocity v₁ₓ = 3 m / s

wind speed 2 v₂ = 10 m / s with direction 65 north of east

          sin 65 = v_{2y} / v₂

          cos 65 = v₂ₓ / v₂

          v_{2y} = v₂ sin 65

          v₂ₓ = v₂ cos 65

          v_{2y} = 10 sin 65 = 9.06 m / s

          v₂ₓ = 10 cos 65 = 4.23 m / s

wind speed 3 v₃ = 8 m / s with direction 70 south of east

This angle measured from the positive side of the x-axis is

          θ = 360 - 70

          θ = 290

          sin 290 = v_{3y} / v₃

          cos 290 = v₃ₓ / v₃

          v_{3y} = v₃ sin 290

          v₃ₓ = v₃ cos 290

           v_{3y} = 8 sin 290 = -7.52 m / s

          v₃ₓ = 8 cos 290 = 2.74 m / s

now we can find each component of the velocity

         

X axis

        vₓ = v₁ + v₂ₓ + v₃ₓ

        vₓ = 3 + 4.23 + 2.74

        vₓ = 9.97 m / s

Y axis  

        v_y = v_{2y} + v_{3y}

        v_y = 9.06 - 7.52

         v_y = 1.54 m / s

to find the modulus let's use the Pythagorean theorem

         v = [tex]\sqrt{v_x^2 + v_y^2 }[/tex]

         v = [tex]\sqrt{9.97^2 + 1.54^2}[/tex]

         v = 10.09 m / s

let's use trigonometry for the direction

         tan θ = v_y / vₓ

        θ = tan⁻¹ v_y / vₓ

        θ = tan-1 1.54 / 9/97

         θ = 8.78

           

the address is 8.78 North of East

The reading on your speedometer is the

A) average velocity
B) none of these is correct
C) speed
D) instantaneous velocity

Answers

The answer is speed!!
If you need why it is speed comment, if helped mark me the brainiest!!
The answer is c) speed

1d. Conservation of energy is demonstrated in this roller coaster example.
The Conservation of Energy is a principle which states that energy cannot be created
or destroyed, but can be altered from one form to another
Friction plays a significant role in the efficiency of the rollercoaster cars. Explain how, even
with friction, the law of conservation of energy still holds true. (2 points)

Answers

Answer:

can you clear your question I can't understand

what happens when a light ray is incident normally to the interface of two media?

Answers

Explanation:

ahhh, maybe you mean , what happens when a light ray hits the interface of two media perpendicular to the normal.

if that is the case then the light ray will not bend but it will travel in the same direction in the second medium as it was travelling in it's first medium

hope this helps bro

Thermal physics vs atomic physics ...which is easier?​

Answers

Answer:

Thermal physics

Explanation:

Because it uses temperature

Answer:

In my opinion both are easier if you'll work hard on it...

Croquet balls must have a mass of 0.50 kg. A red croquet ball is moving at 5 m/s. It strikes an at-rest green croquet ball head-on and then continues to move in the same direction, but with a speed of 2 m/s. What is the final speed of the green ball?

A.
5 m/s

B.
0.5 m/s

C.
2 m/s

D.
3 m/s

Answers

Answer:

Explanation:

The Law of Momentum Conservation for us has the equation

[tex][m_rv_r+m_gv_g]_b=[m_rv_r+m_gv_g]_a[/tex] and filling in:

[tex][(.50)(5.0)+(.50)(0)]=[(.50)(2.0)+(.50)v_g][/tex] and

2.5 = 1.0 + .50v and

1.5 = .50v so

v = 3 m/s

The final speed of the green ball is 3m/s. This can be calculated by the law of conservation of momentum. Thus, the correct option is D.

What is the law of Conservation of Momentum?

The principle of the law of conservation of momentum states that if any two objects undergo collision, then the total momentum of the objects before and after the collision will be the same if there is no external force acting on the colliding objects.

The Law of Conservation of Momentum has the equation which is:

m₁ × u₁ + m₂ × u₂ = m₁ × v₁ + m₂ × v₂

where, m₁ = mass of object 1,

u₁ = initial velocity of object 1 before collision,

m₂ = mass of object 2,

v₁ = final velocity of object 1 after collision,

v₂ = final velocity of the object 2 after collision.

0.50 × 5 + 0.50 × 0 = 0.50 × 2 + 0.50 × v₂

2.5 + 0 = 1.0 + 0.50 × v₂

2.5 - 1.0 = 0.50 × v₂

1.5 = 0.50 × v₂

1.5/ 0.5 = v₂

v₂ = 3m/s

Therefore, the correct option is D.

Learn more about Momentum here:

https://brainly.com/question/24030570

#SPJ2

which of the following is incorrect for nuclear forces
a) they are attractive in nature
b) they are short range forces
c) they obey inverse square law
d) they are non conservative in nature

Answers

Answer:

c they obey inverse square law

Answer is C .

The reason is as follows:
Nuclear forces don’t obey inverse square law.

Neither the strong nuclear force nor the weak nuclear force follow the inverse square law.

The weak nuclear force is a Yukawa-type force. Such a force is characterized by a potential in the form ∝−/

e

m
r
/
r
. At short range ( ≪1
m
r

1
) the exponential term is just 1
1
, so the potential becomes an inverse-
r
potential with an inverse square force law associated with it. So at very short (subatomic) ranges, the weak nuclear force is actually very similar to the electromagnetic force. But as soon as >1
m
r
>
1
, the force rapidly vanishes and becomes undetectable.

The strong nuclear force does not decrease with distance. Which means that as you “stretch” the bond between two quarks, for instance, more and more energy needs to be invested; until there is enough energy to create a new quark-antiquark pair, at which point the bond breaks. This limits the range of the strong nuclear force to subatomic scales, too.

the gravity on mars is 3.8 m/s2 and you weigh 200 N. your mass will be??

Answers

Answer:

Mass = 52.63 kilograms

Explanation:

Given the following data;

Acceleration due to gravity = 3.8 m/s²

Weight = 200 N

To find mass;

Mathematically, the weight of a physical object is given by the formula;

Weight = mass * acceleration due to gravity

Substituting into the formula, we have;

200 = mass * 3.8

Mass = 200/3.8

Mass = 52.63 kg

can someone please help

Answers

Answer: D

Explanation: because doing a yoga desk program is physical activity, 10k steps is pysical activity, riding a bike or walking/running is also physical activity. so it should be D, all of the above.

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