How far away is a RR Lyrae variable star if it has a period of 0.5 days and a brightness of 2.3 x 10^-11 W/m^2?

Explanation:

The angle of incidence is always smaller than the angle of refraction

Answer:

i = -12.7 cm; h =  5.07 cm

Explanation:

1. Find the focal length

The focal length of a concave spherical mirror is half of its radius of curvature.

f = ½r = ½ × 34.0 cm = 17.0 cm

2. Find the image distance

A convex mirror produces a virtual image behind the mirror, so the image distance is negative.

[tex]\begin{array}{rcl}\dfrac{1}{o} + \dfrac{1 }{i} & = & \dfrac{1}{f}\\\\\dfrac{1}{50.0} + \dfrac{1 }{i} & = & \dfrac{1}{-17.0}\\\\\dfrac{1}{i} & = & \dfrac{1}{-17.0} - \dfrac{1}{50.0}\\\\& = & \dfrac{50.0 - (-17.0)}{500\times(-17.0)}\\\\& = & \dfrac{67.0}{-850}\\\\i & = & \dfrac{-850}{67.0}\\\\& = & \textbf{-12.7 cm}\\\end{array}[/tex]

3. Find the image size

[tex]\begin{array}{rcl}\\\\\dfrac{h_{\text{i}}}{ h_{\text{o}}} & = & -\dfrac{i}{o} \\\\\dfrac{h_{\text{i}}}{ 20.0} & = & -\dfrac{-12.7}{50.0} \\\\h_{\text{i}} & = & 20.0 \times \dfrac{12.7}{50.0}\\\\& = & \textbf{5.07 cm}\\\end{array}[/tex]

Answer:

Radio waves have a wavelength between [tex]10^{-9}m[/tex] and [tex]10^{-12}m[/tex]

While,

X rays have a wavelength between 1m and 10km.

=> It is one of the condition of diffraction that the obstacle (coming in the way) must be comparable with the size of the wavelength.

=> This shows, that radio waves have a wavelength which is comparable with the size of buildings and can really easily diffract through it

=> While, X-rays are big enough to diffract through the wall.

So, if an X-ray technician stands behind a wall during the use of her machine, she will remain safe.

Answer:

  (vix, viy) = (14.7 m/s, 10.3 m/s)

Explanation:

The velocities of interest are ...

  (vix, viy) = (vi)(cos(35°), sin(35°)) = (18 m/s)(cos(35°), sin(35°))

  (vix, viy) = (14.7 m/s, 10.3 m/s)

Answer:

First one = 14.7

Second one = 10.3

Explanation:

EDGE

Answer:

[tex]I=0.5 \:A[/tex]  is the correct answer.

Explanation:

Using the ohm's law, we have:

[tex]V=IR\\\\I=\frac{V}{R}=\frac{3}{6}\\\\I=0.5 \:A[/tex]

Best Regards!

Answer:

There must be an equal amount of each element on both sides of the equation. Hope this helps and please marks as the brainliest.

Explanation:

Answer:

The answer is D

Explanation:

Hope this helps!

Answer:

Option(a) i.e" pH" is the correct answer to the given question .

Explanation:

The main objective of pH value is to determining whether the solution is the acidic or the basic solution.The pH is determining the solution whether it is basic or acidic with the help of there pH value .The range of the pH value is from 0 to 14 with the following parameter it determines whether the solution is basic ,acidic or the neutral solution  .

All the other option are not determining that whether the solution is acidic or the basic solution that's why these are incorrect option .

Answer:

the answer is A pH

got it right 2020

Explanation:

Answer:

if i'm not mistaken the answer is A

The new acceleration will be increase by the factor of 2. Hence, option (A) is correct.

Given data:

The mass of body is, m = 40 kg.

We can use the Newton's second law to obtain the result of given problem. As per the Newton's second law, "The force applied by the given object is equal to the product of mass of object and the magnitude of acceleration of object". Then the expression is,

F = ma

a = F/m .....................................................................(1)

Here,

F is the force.

m is the mass.

a is the acceleration.

if the force acting in the mass of body of 40 kg is doubled. Then new acceleration will be,

F' = ma'

(2F) = ma'

2(F/m) = a'

From equation (1) we get,

a' = 2a

Thus, we can conclude that the new acceleration will be increase by the factor of 2. Hence, option (A) is correct.

Learn more about the Newton's Second Law here:

https://brainly.com/question/19860811

Answer: There will be 75258 nuclei left at 6 pm.

Explanation:

a) half-life of the radioactive substance:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.69}{k}[/tex]

[tex]k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{2hours}=0.346hours^{-1}[/tex]

b) Expression for rate law for first order kinetics is given by:

[tex]A=A_0e^{-kt}[/tex]

where,

k = rate constant  

t = time for decomposition = 6 hours ( from 12 noon to 6 pm)

A = activity at time t = ?

[tex]A_0[/tex] = initial activity  = 600, 000

[tex]A=600000\times e^{-0.346\times 6}[/tex]

[tex]A=75258[/tex]

Thus there will be 75258 nuclei left at 6 pm.

Answer:

So the weight of the body is 700N

Explanation:

mass of the object=70kg

force of gravity=10N/kg

weight of the object=w-?

as we know that

weight=mass × force of gravity

weight=70kg × 10N/kg

WEIGHT OF THE BODY=700N

I HOPE IT WILL HELP YOU

GOOD LUCK FOR THE ASSIGNMENT

The correct answer is 700 N.

Object mass = 70 kg

Gravity = 10N / kg

Weight = Mass x Gravity

Weight = 70kg x 10N / kg

Weight = 700 N

Mass is more basic because it is a unique property of the object. Weight varies from place to place depending on the acceleration of gravity. If the mass on the earth is m = 10kg, the weight is W = mg = 10 x 10 = 100N.

The strength of the Earth's gravitational field is 10 Newtons (N / kg) per kilogram. This means that there is a force of 10 Newtons per kilogram on Earth. Mass is the amount of substance that makes up an object.

Learn more about gravitational strength here: https://brainly.com/question/25624188

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Answer:

How you treat someone who may have been poisoned depends on:

The person's symptoms

The person's age

Whether you know the type and amount of the substance that caused poisoning

If you are concerned about possible poisoning, call Poison Help at 800-222-1222 in the United States or your regional poison control center. Poison control centers are excellent resources for poisoning information and, in many situations, may advise that in-home observation is all that's needed.

Answer:

They are the physical parts of a computer.

examples :monitor,keyboard,system unit and mouse.

Answer:

Cloth:

It is an insulator since it can't let electricity pass through

Dry Wood:

It is an insulator and can't conduct electricity.

Tap Water:

It is a good conductor as it contains dissolved salts.

Glass:

It is an insulator since it can't let electricity pass through.

Answer:

Explanation:

ave speed is always (frequency) x (wavelength)

Speed  =  (450 /sec) x (0.52 m)

=      234 m/sec .

Answer:

  500 m

Explanation:

The applicable relation is ...

  wavelength = speed/frequency

  wavelength = (5000 m/s)/(10 cycles/s) = 500 m/cycle

The wavelength is 500 meters.

Answer:

1960 J

Explanation:

EK = (18 kg + 62 kg)[tex](7.0 m/s)^{2}[/tex]/2 = 1960 J

Answer:

The reason is because the pressure of the air inside the room drops with time which makes opening the door to require an increased amount of force to make up for the reduced pressure inside the room

Explanation:

From the kinetic theory of gases we have the following relation;

[tex]v_{rms} = \sqrt{\dfrac{3 \cdot K \cdot T}{m} }[/tex]

[tex]p = \dfrac{n \cdot MW \cdot v^2_{rms} }{3 \cdot V}[/tex]

Where:

K = Boltzmann constant

T = Temperature

m = Mass

MW = Molecular weight

V = Volume

[tex]v_{rms}[/tex] = Root mean square velocity

Whereby the room door is closed, the kinetic energy of the air particles will be used up such that the average velocity of the particles will decrease, given that the volume of the room is constant, the pressure inside the room will drop below the original pressure outside the room such that the force on the door due to the outside pressure is larger than the force on the door from inside the room requiring a larger amount of force to overcome the resistance of the now higher outside pressure force.

Answer:

Socialist

Explanation:

Answer: socialist

Explanation: A socialist form of government is where the goods and services are equally shared, and the political power is distributed among the people.

Answer:

The substances which allow an electric current to pass through it is called conductors.

Example: Metals like copper,iron ,graphite etc.

The substances which do not allow the electric current to pass through is called Insulators.

Example: Glass, dry wood ,plastic etc.

Hope this helps...

Good luck on your assignment...

Answer:

The most of the elements in the periodic table are metals. The elements cannot be gases and liquids (Molecules are mainly gases and liquids). Metalloids are few. Examples (Germanium, Arsenic)

Wood is a natural insulator due to air pockets within its cellular structure, which means that it is 15 times better than masonry, 400 times better than steel, and 1,770 times better than aluminum. In addition, lightweight wood framing methods allow easy installation of additional fibre or foil insulation. i hope this is better

Answer: B

V = 7576 m/s

Explanation: Given that the

circular radius R = 7,000,000 m,

The acceleration due to Earth's gravity is 8.2 m/s2

Let's use gravitational field strength formula to get the mass of the satellite.

g = Gm/R^2

Where G = 6.674×10^−11m3⋅kg−1⋅s−2

Substitutes all the parameters into the formula

8.2 = (6.674×10^-11 × M)/(7000000)^2

Cross multiply

4.018 × 10^14 = 6.674×10^−11M

Make M the subject of formula

M = 4.018 × 10^14 ÷ 6.674×10^−11

M = 6.02 × 10^24 kg

The Force of attraction experienced by the satellite will be

F = mg

F = 6.02 × 10^24 × 8.2

F = 4.94 × 10^25 N

But centripetal force is

F = MV^2/ R

Where V = velocity of the satellite

Substitute F, M and R into the formula

4.94×10^25 = (6.02×10^24V^2)/ 7 ×10^6

Cross multiply

3.46 × 10^32 = 6.02×10^24V^2

Make V^2 the subject of formula

V^2 = 3.46×10^32 ÷ 6.02×10^24

V^2 = 57403600.2

Find the square root of the value to get V

V = 7576 m/s

The required velocity of the satellite is 7576 m/s approximately

Answer: If i'm not mistaken I think it A) potential

Answer:

a 1.26 km b 10.5 m/s

Explanation:

A. Distance travelled by the schooterist

Since the schooterist travels in a circular path, the distance moved is the circumference of a circle, C with radius r = 0.2 km

C = 2πr

= 2π(0.2 km)

= 1.26 km

So, the distance travelled by the schooterist is 1.26 km

B. The velocity of the schooterist

The velocity of the schooterist v = distance travelled/time

distance travelled = 1.26 km = 1260 m

time = 2 minutes = 2 × 60 s = 120 s

So, V = 1260 m/120 s

= 10.5 m/s

So, the velocity of the schooterist is 10.5 m/s

Answer:

  The acceleration would double

Explanation:

Assuming the same box and spring, the maximum acceleration is proportional to amplitude. When the amplitude doubles, the acceleration would double.

__

A spring is generally considered to have a linear force vs. distance characteristic. Hence, doubling the distance doubles the force. The acceleration is proportional to the force.

Note that the correct times are t = 0, t = 1/4, t = 1/2. You can tell from the spaces between the two digits. i.e 1&4 and 1&2

Answer:

y(0) = 2.00 cm

y(1/4) = 1.56 cm

y(1/2) = 1.21 cm

Explanation:

This is a very simple exercise, the displacement of the oscillating weight from equilibrium has already been modeled by the equation:

[tex]y(t) = 2e^{-t} cos 4t[/tex]

Where y = displacement ( in cm)

and t = time (in seconds)

The task is to find the displacement when t = 0, 1/4 and 1/2

When t = 0 s

[tex]y(0) = 2e^{0} cos 4(0)\\y(0) = 2* 1*1\\y(0) = 2.00 cm[/tex]

When t = 1/4 s

[tex]y(1/4) = 2e^{-1/4} cos 4(1/4)\\y(14) = 2e^{-1/4} cos (1)\\y(1/4) = 1.56 cm[/tex]

When t = 1/2

[tex]y(1/2) = 2e^{-1/2} cos 4(1/2)\\y(14) = 2e^{-1/2} cos (2)\\y(1/2) = 1.21 cm[/tex]

Answer:

T = 0.00025 secs

Explanation:

Given:

Frequency = 4 kHz = 4000 Hz

Required:

Time Period = ?

Formula:

T = 1/f

Solution:

T = 1/4000

T = 0.00025 secs

Answer:

0.00025 seconds

Explanation:

Time period = 1 / frequency

= 1/4000

= 0.00025 seconds

Hope this helps, and please mark me brainliest if it does!

Answer:

a. All the laboratory equipment given are very basic equipment used in all the laboratories. Name of each equipment is as follows:

b. Use of each laboratory equipment identified is: