7. Sally was trying to create a model that represents the composition of a galaxy. In her model, she needs to distinguish galaxies from other systems of celestial objects.
Which of the following best describes the composition of a galaxy?

0.23 A across the 20-ohm resistor

Explanation:

The 20-ohm and 35-ohm resistors are in parallel so their combined resistance is

(1/20) + (1/35) = 0.0786 ohm^-1 or 12.73 ohms

These two are in turn connected in series with the 15-ohm resistor so the total resistance of the circuit is

R = 12.73 ohm + 15 ohm

= 27.73 ohm

Hence, the total current drawn by the circuit is

I = V/R = (10 V)/(27.73 ohm)

= 0.36 A

The potential across the 15-ohm resistor is

V1 = IR = (0.36 A)(15 ohm)

= 5.4 V

Now the potential across the 20-ohm and 35-ohm resistors is

V2 = V - V1 = 10V - 5.4V

= 4.6 V

This means that the current across the 20-ohm resistor is

I = V/R = (4.6 V)/(20 ohm)

= 0.23 A

Answer:

Answer would be 0.23

Explanation:

Put in 0.23

Answer:

There are four natural states of matter: Solids , liquids, gases and plasma. The fifth state is the man-made Bose-Einstein condensates. In a solid, particles are packed tightly together, so they don't move much.

Explanation:

Answer: B

Explanation: The higher temperature increases the reaction rate but also favors the reverse read on.

The higher temperature increases the reaction rate, but it also favors the reverse read on. So, option B.

The pace at which the products are created from the reactants in a chemical reaction is referred to as the rate of reaction.

Here,

Generally, reactions progress more quickly as the temperature rises.

The average kinetic energy of the reactant molecules will rise with a rise in temperature. The number of molecules having threshold energy rises, increasing the quantity of efficient collisions that actually occur.

Therefore, as the temperature of the reaction is increased, the rate of the reaction increases. But also favors the reverse reaction.

Hence,

The higher temperature increases the reaction rate, but it also favors the reverse read on.

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Answer: First stage

Explanation:

The four stages of technological design include:

• identifying a problem.

• Designing a solution.

• Implement, build, and test the design.

• Determine if solution met the need.

In this scenario, Robert Shuman identified the problem. This was depicted as he stated that coal and oil would eventually run out and that humans needed to learn how to use the more-abundant energy resource of the Sun,

sea water is the answer to your question

Answer:

Hey mate.....

Explanation:

This is ur answer.....

Sound travels faster in steel than in water. Similarly, sound travels faster in water than in air. This is because in solids, the distances between the molecules are closer and thus the atoms are more densely packed than in gases and liquids

Hope it helps!

Brainliest pls!

Follow me! :)

Answer:

voltage ,current and resistance

Answer:

θi = 47.7°

Explanation:

The formula for the refractive index is as follows:

[tex]n = \frac{Sin\theta_i}{Sin\theta_r}[/tex]

where,

n = refractive index = 1.75

θi = angle of incidence = ?

θr = angle of refraction = 25°

Therefore,

[tex]1.75 = \frac{Sin\ \theta_i}{Sin\ 25^o} \\\\(1.75)(Sin\ \ 25^o) = Sin\ \theta_i\\\\\theta_i = Sin^{-1}(0.739)[/tex]

θi = 47.7°

Answer:

Acceleration is defined as the rate of change of velocity

Explanation:

Its A

Answer:

(a) 1320 W

(b) 480 W

(c) E':E ≈ 11:2

Explanation:

(a) Applying,

P' = VI'................. Equation 1

Where P' = Power of the blow-dryer, V = Voltage, I = current rating of the blow-dryer.

From the question,

Given: V = 120 V, I' = 11 A

Substitute these values into equation 1

P = (120×11)

P = 1320 W

(b) Similarly,

P = VI................... Equation 2

Where P = Power of the vacuum cleaner. I = current rating of the vacuum cleaner.

Also Given: I = 4 A,

Therefore

P = 4(120)

P = 480 W

(c)

E' = P'/t'............. Equation 3

E = P/t................ Equation 4

Where E' = Energy of the blow-dryer, t' = time of use of the blow-dryer, E = Energy of the vacuum cleaner, t = time of use of the vacuum cleaner

From the question,

Given: t' = 15 minutes = (15×60) = 900 seconds, t = 30 minutes = (30×60) = 1800 seconds

Substitute these values into equation 3 and 4

E' = 1320/900

E' = 1.47 J,

E = 480/1800

E = 0.267

Therefore,

E':E = 1.47:0.267

E':E ≈ 11:2

Answer:

2. Given:

m=1000Kg

a=(9.8m/s)^2

F=m×a

=9.8×1000

=9800N

3.Given:

m=50kg

f=500N

F=m×a

500N=50Kg×a

50kg×a=500N

a=500÷50

a=(10m/s)^2

Answer:

Explanation:

B

Explanation:

Because, there is not atmosphere in vacuum. So, sound does not propagate through a vacuum.

Answer:

Explanation:

This is quite tricky! You need to do 2 different equations to solve all the parts of this problem. First is finding the acceleration in one dimension, which has an equation of

F - f = ma

where F is the applied Friction,

f is the frictional force acting against F,

m is the mass of the object, and

a is the acceleration of the object (NOT the velocity!)

This is Newton's Second Law expanded on a bit. The sum of the forces working on an object is equal to the object's mass times its acceleration. We have F, but we need f which is found in the equation

f = μ[tex]F_n[/tex] which is the coefficient of kinetic friction times the weight of the object. Weight is found in the equation

w = mg where m is mass and g is the pull of gravity. Let's start there and work backwards:

w = 37(9.8) to 2 sig figs so

w = 360N. Now fill that in to find f:

f = (.17)(360) to 2 sig figs so

f = 61. Now for the final answer in the original equation way back up at the top:

85 - 61 = 37a and do the subtraction on the left side first:

24 = 37a and then we divide to 2 sig figs to get

a = .65 m/s/s

Since we are moving in a straight line (as opposed to on an angle) the displacement is found in

d = rt which simply says that the distance an object moves is equal to its rate times the time. Therefore,

d = 2.2(3.4) to 2 sig figs so

d = 7.5 m

Answer:

Explanation:

We need the power equation for this which is

P = Work/time

We have everything we need to solve this (the mass of the object is extra information):

P = 6860/4

P = 1715W

Answer:

A: -2.6 × 10^(-6) C and 2.6 × 10^(-6) C

Explanation:

According to coulombs law, the formula for the force between 2 charged particles is;

F = kq1•q2/r²

Where;

F is Force = |1N|

q1 and q2 are the charges of both particles

k is coulombs constant = 9 × 10^(9) N.m²/C²

r is distance between particles = 0.25

Now, the force |1N| means -1 or +1

Thus;

-1 = 9 × 10^(9) × q1•q2/(0.25)²

Or

1 = 9 × 10^(9) × q1•q2/(0.25)²

Thus;

q1•q2 = -6.94 × 10^(-12)

Or q1•q2 = 6.94 × 10^(-12)

Now, we are told that the magnitude of both charges are the same.

Thus;

q² = 6.94 × 10^(-12)

q = √(6.94 × 10^(-12))

q = 2.6 × 10^(-6) C

Since from earlier, we saw that;

q1•q2 = -6.94 × 10^(-12)

Or q1•q2 = 6.94 × 10^(-12)

Thus means that one of the charges will be negative while the other will be positive.

Thus, the charges are;

-2.6 × 10^(-6) C and 2.6 × 10^(-6) C

Answer:

100 kg

Explanation:

F = 400 N

a = 4 m/s

F = ma

400 = m(4)

m = 100 kg

Answer:

Explanation:

use formula,

Force=mass*acceleration

400 N=mass*4m/s

400 N/4 m/s=mass

100 kg =mass

Answer

gas, dust, and billions of stars and their solar systems, all held together by gravity.

Explanation:

Answer:

Galaxies are a group of stars held together by gravity.

Answer:

The energy was stored as chemical energy in Sue' muscle before it was transformed into mechanical energy that moves the pump handle to ump the tyre

Explanation:

In pumping up the tyre, the valve of manual pump is attached airtight to the tyre tube

As the handle of the pump is pulled up or out, air rushes into the pump from the atmosphere through the inlet valve

As the handle pushed in, the inlet valve closes and the air is forced into the tyre tube by difference in pressure and as the tube is filled, more pressure is required to enable the tube expand and build pressure inside to maintain a circular cross section while carrying load

According to Gay Lussac's Law, temperature of the air in the pump increases as its pressure increases

Given that Sue provides the energy for pumping the tyre, the energy was stored as chemical energy in Sue's muscles which is then used in moving the pump handle in the up and down motion required to pump the tyre

Answer:

The friction of braking heats up the tire and the road. The temperature is so high that it reaches the melting point of the rubber in the tire. The melting rubber is what leaves a mark on the road.

Explanation:

Answer:

the friction of braking heats up the tires and the road. then the temperature gets even hotter to the point where it melts the rubber.

Explanation:

this is my answer so be careful how you copy it, but you've got this guys schools is almost out stay strong an have fun and be safe this summer keep pushing <33.

remember you're loved by many

- Jason Edwards 5/15/23

Covalent

Explanation:

Covalent Bond

Answer:

diphosphorus trioxide

Explanation:

Answer:

Building is 747.19 m tall

Explanation:

Given, t

Total velocity v = 123 m/s

Horizontal velocity or the X -component if velocity vx = 22 m/s

For a horizontal projectile motion  

V = Sqrt (vx^2 + g^2t^2)

Or t = sqrt{(v^2 – vx^2)/g^2} ---Eq (1)

Time of flight  

t = sqrt (2h/g) – Eq (2)

where h is the height

Equating, both the equation, we get –  

h = (123^2 – 22^2)/19.6 = 747.19 m

Answer:

1) - 35

2) - 35

3) - 67

4) - 83

Answer:

S = 26.58 meters

Explanation:

Given the following data;

Initial velocity = 4.66 m/s

Acceleration = 5.66 m/s²

Time = 2.35 seconds

To find the distance travelled by the object, we would use the second equation of motion;

S = ut + ½at²

Where;

S represents the displacement or height measured in meters.

u represents the initial velocity measured in meters per seconds.

t represents the time measured in seconds.

a represents acceleration measured in meters per seconds square.

Substituting into the equation, we have;

S = 4.66*2.35 + ½*5.66*2.35²

S = 10.951 + (2.83 * 5.5225)

S = 10.951 + 15.629

S = 26.58 meters

Precaution: balance the ruler being used first.

Precaution: balance the ruler being used first.Use distances from the pivot of greater than 25 cm (250 mm).

Precaution: balance the ruler being used first.Use distances from the pivot of greater than 25 cm (250 mm).Weigh the unknown and known masses in your hands before using the ruler, and place the lighter mass as far from the pivot as possible.

Precaution: balance the ruler being used first.Use distances from the pivot of greater than 25 cm (250 mm).Weigh the unknown and known masses in your hands before using the ruler, and place the lighter mass as far from the pivot as possible.Measure distances from the pivot to the centre of mass of the object.

Answer: 1.67 m/s

Explanation:

Given

Mass of bag is [tex]m=8.6\ kg[/tex]

Mass of cart is [tex]M=18.1\ kg[/tex]

bag hits the cart with horizontal speed of [tex]u=5.2\ m/s[/tex]

Suppose the system move with speed v after collision

Conserving the momentum

[tex]\Rightarrow mu+M(0)=(M+m)v\\\\\Rightarrow v=\dfrac{mu}{M+m}\\\\\Rightarrow v=\dfrac{8.6\times 5.2}{18.1+8.6}\\\\\Rightarrow v=1.67\ m/s[/tex]

The correct answer to this open question is the following.

Unfortunately, you did not attach the article or the text. You also forgot to attach the options for the question.

However, trying to help you we did some deep research and can comment on the following.

The statement that describes the central idea of the text is "Baseball can be explained and improved by collecting data and studying the natural laws at play in the sport."

You are referring to the article written by Stephen Ornes, of August 21, 2013, for Science News for Students.

The author refers to the idea that baseball and physics are related and can be understood through the "eyes" of science. Statistics bring interesting data to help understand the game.

And this idea is correct because today, baseball coaches and other sports coaches as is the case of football, use a series of statistics and data to better hire talent for their respective teams, as well as to better create plans and game strategies derived from the results and interpretation of data.