Which statements describe properties of stars? Check all that apply.
Stars produce energy through nuclear fusion.
Stars produce energy through gravity.
Stars are massive objects composed of gas.
Stars are solid objects that we could stand on.
Stars are composed primarily of hydrogen and helium.
Stars are composed primarily of liquids such as water.

Answer : A concave mirror is used to converge the light and a convex mirror is used to diverge the light.

Explanation :

Convex mirror : In convex mirror, the mirror is coated inside the spherical surface. It is also known as a converging mirror.

The focus lies behind the mirror.

Concave mirrors : In concave mirror, the mirror is coated outside the spherical surface. It is also known as a diverging mirror.

The focus lies infront the mirror.

As per question, a concave mirror is used to converge the light and a convex mirror is used to diverge the light.

Hence, a concave mirror is used to converge the light and a convex mirror is used to diverge the light.

Answer:

218.5 N

Explanation:

In order for the sled to be in equilibrium along the vertical direction, the forces acting along this direction must be balanced. So the equilibrium equation is:

[tex]N+F sin \theta - mg =0[/tex]

where

N is the normal force

F = 50 N is the force that pulls the sled

[tex]\theta[/tex] is the angle between the force and the horizontal, so

[tex]F sin \theta[/tex] is the component of F acting along the vertical direction

(mg) is the weight of the sled, with

m = 25 kg being the mass of the sled

g = 9.8 m/s^2 is the acceleration due to gravity

Solving the formula for N, we find

[tex]N=mg-F sin \theta = (25 kg)(9.8 m/s^2)-(50 N)sin 32^{\circ}=218.5 N[/tex]

By resolving into y - component, the normal force acting on the sled is 218.5 N.

Force is the product of mass and acceleration. Where a frictional force is negligible, the resultant force will be equal to the force applied.

Given that Jake drags a sled of mass 25 kg across the snow. The sled is attached to a rope that pulls with a force of 50 N at an angle of 32 degrees.

If g is taken to be 9.8 m/s^2, the forces acting on the mass are:

The weight mg = 25 x 10 = 245 N

The normal reaction N = ?

The applied force F which can be resolved into x and y components

x - component = 50 x cos 32 = 42.4N

y - component = 50 x sin 32 = 26.5 N

If there is no friction, the normal force acting on the sled can be calculated by resolving all the forces into x and y component.

By resolving into y - component,

N + 26.5 = 245

N = 245 - 26.5

N = 218.5 N

Therefore, the normal force acting on the sled is 218.5 N.

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Answer:

1. D) group; the same number of valence electrons

A group is a column in the periodic table where elements have the same number of valence electrons. Sodium and Chlorine bond to form table salt through an ionic bond.

A column in the periodic table is called a group. Elements in each group have the same number of valence electrons. This means that they have similar chemical properties and tend to react in similar ways.

Sodium (Na) and Chlorine (Cl) bond to form table salt (NaCl) through an ionic bond. Na transfers an electron to Cl, resulting in the formation of Na+ and Cl- ions. The opposite charges of the ions attract each other, creating the ionic bond in NaCl.

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Work = (force) x (distance)

Work = (22 N) x (16 m)

Work = 352 Joules

Answer:

352 jules

Explanation: please leave a rating

Answer:C

Explanation:

Total Resistance=R1+R2

R1=2*5=10ohms

R2=3*20=60ohms

Therefore; Total R=10+60

=70ohms

The total resistance of the series circuit is calculated by adding the resistances of all the individual components. By calculating and adding together the total resistance for the fans and the lights, you find that the total resistance for the circuit is 70 ohms.

In a series circuit, the total resistance is obtained by simply adding up all the individual resistances within the circuit. Therefore, to find the total resistance of John's circuit, you need to multiply the number of each component by its resistance and add these totals together.

For the fans: 2 fans × 5 ohms per fan = 10 ohms.

For the lights: 20 lights × 3 ohms per light = 60 ohms.

Adding these two totals together gives the total resistance of the circuit: 10 ohms + 60 ohms = 70 ohms. So the total resistance of the circuit is 70 ohms, making the answer choice C. correct.

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Answer:

Competition

Explanation:

Answer:

5.3 A

Explanation:

The orbital radius for the generic nth-level in the hydrogen atom is given by

[tex]a_n = n^2 a_0[/tex]

where:

[tex]a_0 = \frac{\epsilon_0 h^2}{\pi m_e e^2}[/tex]

is the Bohr radius, with

[tex]\epsilon_0 = 8.85\cdot 10^{-12} F/m[/tex] being the vacuum permittivity

[tex]h=6.63\cdot 10^{-34}Js[/tex] is the Planck constant

[tex]m_e = 9.11\cdot 10^{-31} kg[/tex] is the electron mass

[tex]e=1.6\cdot 10^{-19} C[/tex] is the electron charge

Substituting all this numbers into the formula, we find

[tex]a_0 = 5.3\cdot 10^{-10} m = 5.3 A[/tex]

and since

n = 1

the radius of the hydrogen atom for the first principal quantum number is

[tex]a_1 = 1^2 a_0 = 1 \cdot (5.3 A)=5.3 A[/tex]

Answer:

0.53 A

Explanation:

Answer:

1  seesaw = first class lever

2. pencil and sharpener = wheel and axle

3. bottle opener = second class lever

4. forearm = third class lever

5. nail = wedge

Explanation:

The given objects are classic examples of simple machines.

Lever: There are 3 types of levers and they depend on where the load, applied force, and fulcrum are.

First class levers have the fulcrum in between the load and the applied force. In other words, the load and applied force are at opposite ends. The seesaw is a good example of this. Other examples would be, pliers, scissors, and the like.

Second class levers have the fulcrum and the applied force at the opposite ends. So in this case, the load is found in between. Examples of this would be a bottle opener or a crowbar.

For third class levers, the load and the fulcrum are at opposite ends and the applied force is in between. The forearm is a good example, so is a stapler, or even a broom.

A wedge is another simple machine. It is thick at one end and it gets thinner towards the other end, or it usually has a sharp end. Other examples of this would be an axe, or a knife.

A sharpener is actually a compound machine. The old-fashioned type of pencil sharpener, the one you crank makes use of a wheel and axle and a wedge. A wheel and axle is usually a machine that makes use of two circular parts; a wheel and a rod that is attached to its center.

Final answer:

The list involves identifying simple machines such as lever, wheel and axle, and the wedge. Key corrections include seesaw as a first-class lever, pencil sharpener utilizing wheel and axle, and a nail being a wedge.

Explanation:

The classification of the items listed involves understanding the basic types of simple machines recognized since the Renaissance—lever, wheel and axle, pulley, inclined plane, wedge, and screw. These machines serve as the foundational building blocks to explain how more complicated machines work, offering a mechanical advantage by altering the magnitude or direction of forces. Renaissance scientists identified these six simple machines as crucial in understanding mechanical principles.

A seesaw is an example of a first-class lever, where the fulcrum is between the input force and the load.

A pencil sharpener uses a wheel and axle, which consists of a rod (the axle) fixed to the center of a wheel, simplifying the twisting motion.

A bottle opener typically functions as a second-class lever or sometimes as a lever of another class, depending on its design, where the load is between the fulcrum and the effort.

The forearm acts as a lever within the human body, showcasing how levers are crucial in the design of living organisms for movements such as flexing and extending.

A nail is best described as a wedge, which is essentially two back-to-back inclined planes that apply force over a wider area.

Error corrections in the initial classification include identifying the seesaw as a first-class lever, the bottle opener's potential as a second-class lever depending on its design, the pencil sharpener as involving wheel and axle mechanics, the forearm as a biological example of lever mechanics, and finally, recognizing a nail as a form of wedge, not a lever.

Answer:

Strong nuclear force

Explanation:

Strong nuclear force is the answer for A P E X

Speed = (distance covered) / (time to cover the distance)

Speed = (525 km) / (1.25 hrs)

Speed = (525/1.25) km/hr

Speed = 420 km/hr

Velocity = speed and the direction from start to finish

Velocity = 420 km/hr North

Velocity of a object is the ratio of distance covered by the object to the time taken by it. The velocity of the airplane is 420 kilometre per hours.

Given information-

The total distance covered by the airplane in north direction is 525 kilometres.

The total time taken by the airplane to cover this distance is 1.25 hours.

Velocity of a object is the ratio of distance covered by the object to the time taken by it.

It can be given as,

[tex]v=\dfrac{x}{t}[/tex]

Here, [tex]x[/tex] is the distance covered by the object and [tex]t[/tex] is time taken by it.

As he total distance covered by the airplane in north direction is 525 kilometres and the total time taken by the airplane to cover this distance is 1.25 hours.

Thus the velocity of the body can be given as,

[tex]v=\dfrac{525}{1.25}\\v=420[/tex]

Hence the velocity of the airplane is 420 kilometre per hours.

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Answer:

It takes 3.31 s for the boy to hear the returning sound of the stone

Explanation:

Ok, the time after which splash is heard is equal to the time acquired by the stone to reach the ground + time taken by sound to return.

First, u=0 m/s (this is the initial speed with which the stone was thrown), h=50 m (is the height of the tower) and g=10 m/[tex]s^{2}[/tex] (is the gravity)

We can use this equation that relates the free fall of the object:

[tex]h=u+\frac{1}{2} gt^{2}[/tex]

[tex]50=0+\frac{1}{2}(10)t^{2}[/tex]

[tex]50=5t^{2}[/tex]

[tex]10=t^{2}[/tex]

and [tex]t=\sqrt{10}=3.16 s[/tex]

t =3.16 s is the time it takes the stone to fall

Second, h=50 m and v=340 m/s (that it's the speed of sound)

We can use this equation:

[tex]h=vt[/tex]

[tex]t=\frac{h}{v}[/tex]

[tex]t=\frac{50}{340}=0,15 s[/tex]

t=0.15 is the time it takes for the sound to return

Finally, both times are added, obtaining the time in which the boy will hear the returning sound of the stone:

[tex]t= 3.16 s + 0.15s[/tex][tex]=3.31 s[/tex]

Answer:

C. No additional heat is required to make it occur

Explanation:

A reaction is said to be spontaneous if it can occur on its own. Spontaneous reactions do not require additional energy or heat from other sources to occur.

A spontaneous reaction leads to an increase in the disorderliness of a system.

We can use the free energy change of a system which measures the energy of a system used to useful work to predict the spontaneity of a reaction.

If the Free energy change is negative the reaction is said to be spontaneous or feasible.

Answer:

1,350 J

Explanation:

According to the work-energy theorem, the work done equals the change in kinetic energy.  So W = 1,350 J.

A 60.0 kg runner is moving at 6.00 m/s and speeds up to 9.00 m/s. Hence, The work done on the runner is 810 J.

Given:

ΔKE = 1,350 J

The change in kinetic energy (ΔKE) is equal to the work done on the runner (W).

ΔKE = W

Given:

ΔKE = 1,350 J

ΔKE = KE(final) - KE(initial)

KE(initial) = (1/2) × m × (initial velocity)² =  (1/2) × 60.0 × (6.00)² =  540 J

KE(final) = (1/2) × m × (final velocity)² = (1/2) × 60.0 × (9.00)² =  1,080 J

Now, we can find the work done is:

ΔKE = KE(final) - KE(initial)

1,350 = 1,080 - 540 + W

1,350= 540 + W

W = 810 J

Therefore, the work done on the runner is 810 J.

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Answer:

Blue

Explanation:

The answer isssss Blue

Melting ice is not a chemical reaction, but is a physical change. There is no chemical reaction involved during the melting process, and it is still the same molecular substance.

Answer:14,400 watts :)

Explanation:

Answer:

12.6 cm

Explanation:

We can use the mirror equation to find the distance of the image from the mirror:

[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}[/tex]

where here we have

f = 9.50 cm is the focal length

p = 39 cm is the distance of the object from the mirror

Solving the equation for q, we find:

[tex]\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{9.50 cm}-\frac{1}{39 cm}=0.080 cm^{-1}\\q = \frac{1}{0.080 cm}=12.6 cm[/tex]

Answers: B) distance=10km

A) displacement=0km

Distance is a scalar of total unit distance travelled not depending upon path taken.

Displacement is a vector of unit displacement travelled along according to the path taken. So if we go 5km north and then go another 5km south to return home we have not had any displacement as we ended back at our starting point.

Hope this helps you understand some. Any questions feel free to ask. Thank you.

Answer:

Herpetology is the branch of zoology concerned with reptiles and amphibians.

Answer:

birds

Explanation:

im taking the test rn

Answer:

A scientific law is a statement based on repeated experimental observations that describes some aspect of the world. A scientific law always applies under the same conditions, and implies that there is a causal relationship involving its elements

Answer:

An object at rest will remain at rest unless an unbalanced force acts upon it.

Study Island Answer

Answer:

Motion of tides in the sea.

Explanation:

The motion which does not repeat itself after the regular interval of time is called non-periodic motion.

Non-periodic motion refers to movement that does not repeat in a regular pattern. The Foucault pendulum is an example, as its plane of oscillation rotates due to Earth's rotation, distinguishing it from periodic motions like simple harmonic motion.

Examples of Non-Periodic Motion

An example of non-periodic motion is the motion of a projectile, such as a ball thrown into the air. Unlike periodic motion, non-periodic motion does not repeat itself in a regular pattern over time. The Foucault pendulum is a classic example of motion in non-inertial frames and is often mistaken as exhibiting periodic behavior. However, while a simple pendulum oscillates back and forth in a regular manner, the plane of oscillation of the Foucault pendulum gradually rotates due to the Earth's rotation, which is an example of non-linear motion. This slow rotation cannot be characterized by a single period, distinguishing it as non-periodic motion.

In contrast, simple harmonic motion (SHM) is a classic representative of periodic motion. An example of SHM is a mass attached to a spring that moves back and forth; its displacement can be represented as a sine wave function, indicating its periodic nature. Such systems have defining quantities like amplitude, period, and frequency, which do not apply to non-periodic motions.

Other examples of non-periodic motion might include a leaf falling from a tree, a car navigating through city traffic, or the random motion of a gas particle, which do not repeat consistently and lack a regular period.

If both the atomic number and mass number each increased by one, then ...

-- the atom would have one more proton in its nucleus,

and

-- whenever it was in a neutral state, it would also have one more electron in its cloud.

choice - B

Answer:

The solar radiation is one of the main factors that shapes the climate all over the globe, so the climate differs with the less or more solar radiation it gets. The polar regions are cold, this is due to the fact that the solar radiation in here is very obscure, because the solar radiation falls at a very wide angle the heat is dispersed over larger area, thus the land gets very little warmth. The Equator, on the other hand, gets direct solar radiation, the sun light falls at a 90 degrees angle or close to it, so the radiation is more concentrated on a smaller area, thus the warming is bigger.

* hopefully this helps:) Mark me the brainliest:)!!!

Final answer:

Solar radiation impacts the equator and polar regions differently; the equator receives more direct sunlight, resulting in higher temperatures and less seasonal variation, while the polar regions receive oblique rays that lead to less intense solar radiation and increased seasonal temperature extremes. The Earth's oceans and atmosphere redistribute heat, and the tilt of the Earth contributes to seasonal differences in climate.

Explanation:

The solar radiation affects the climate differently at the equator compared to the polar regions due to the Earth's curvature and tilt. Near the equator, solar radiation is more direct, leading to higher temperatures and more consistent climatic conditions throughout the year. In contrast, polar regions receive oblique rays, resulting in less intense solar radiation and more extreme seasonal variations in temperature.

Oceans and the atmosphere work together to redistribute this heat, moderating climates by transferring warmth from equatorial regions to the poles. This is facilitated by ocean currents and atmospheric circulation, which move heat laterally across the planet, bringing about a more balanced climate globally. The presence of ice and snow in polar regions, with high albedo, reflects significant amounts of solar radiation, further reducing the energy absorbed in these areas.

Throughout the year, solar radiation varies based on latitude, with regions between 23.5 degrees north and south experiencing the highest amounts of solar radiation during the equinoxes. The changing angles of solar radiation due to the Earth's tilt contribute to seasonal differences, with more direct sunlight during summer months leading to warmer temperatures and an increased angle during winter causing more reflected sunlight and cooler temperatures.

Answer: Option 'D' is correct.

Explanation:

Earth has one natural satellite i.e. "Moon".

Earth spins on its axis due to moon is tidally locked.

The mass of moon is much greater than the mass of earth.

The age of moon is much older than the age of Earth.

The moon is older than Earth by approximately 300 million years.

so, only one statement is  correct i.e. 'D'.

Hence, Option 'D' is correct.

Answer:

TOOK THE TEST AND GOT IT WRONG! D IS NOT THE ANSWER!!

Explanation:

Hope this helps! have a good day!

Hello There!

Because kinetic energy is proportional to the square of the velocity, when velocity is doubled, kinetic energy is quadrupled.

In the absence of air resistance, projectiles exhibit accelerated vertical motion due to gravity and constant horizontal motion, as there is no horizontal force acting upon it.

Assuming no air resistance, all projectiles exhibit C) accelerated vertical motion and constant horizontal motion.

In physics, the motion of a projectile under gravity is divided into two components: vertical and horizontal. The vertical motion of a projectile is influenced by the force of gravity, which causes a constant acceleration downwards. This is why when a projectile is launched, it moves upwards slowing down until it reaches a peak, and then accelerates downwards as it falls. The force of gravity does not affect the horizontal motion, which remains constant assuming no air resistance.

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Final answer:

The answer is C) accelerated vertical motion and constant horizontal motion, due to gravity's constant acceleration acting vertically and no horizontal forces acting after launch.

Explanation:

The correct answer to the student's question is C) accelerated vertical motion and constant horizontal motion. In projectile motion, assuming no air resistance, the horizontal component of the motion has a constant velocity because there is no force acting in the horizontal direction once the object is in flight. However, the vertical component is influenced by the constant acceleration due to gravity (9.80 m/s2 downward). Thus, the vertical motion of a projectile is always accelerating downward at a constant rate, while the horizontal motion proceeds at a constant velocity.

One way to think about this is to imagine throwing a ball forward; the ball will move horizontally at the speed you threw it (ignoring air resistance) but will also begin to fall vertically due to gravity. This results in a characteristic parabolic motion, which is a path that the projectile follows under the influence of only constant gravitational acceleration.

Answer:

All of the above

Explanation:

Astronomers use all of those measures to classify stars. If you want to look more into classifying stars, check out the Hertzsprung-Russel Diagram. It covers how to identify red giants, main sequence, dwarf stars, ect. Distance from earth is typically measured in light years. The color of stars generally determines how hot they are. (Blue stars are the hottest) Also, the parallax method is used to measure stars that are closer to earth. This method relies heavily on geometry though.

Hope this helped!

Adding a battery in a circute has effect of producing push from the more batteries acting together which helps to move the charged particle around the circute more quickly.

This means that the more charged particles per second pass any point in circuit and so the size of electric current is increased.

Answer:

the answer is B ,

Explanation:  because fusion reactors in concept would use hydrogen.

The fission reactor, different from a fusion reactor. Because he fuels must be processed in the fission reactor. Option B is correct.

The process by which two or more tiny nuclei unite to generate a bigger nucleus is known as a nuclear fusion reaction.

The fission reactor, different from a fusion reactor. Because he fuels must be processed in the fission reactor.

Hence, option B is correct.

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Q = 3.973x10⁻⁷C.

The key to solve this problem is using the equation of a parallel plate capacitor.

C = Q/Vᵃᵇ = ε₀ A/d Where C is the capacitance, Q is the charge placed on the plates, Vᵃᵇ is the potential difference between the plates, ε₀ is the constant of the permittivity of vacuum, A is the area of the plates, and d is the separation of the plates.

Clear Q from the equation Q/Vᵃᵇ = ε₀ A/d:

Q = ε₀AVᵃᵇ/d

With ε₀ = 8.85x10⁻¹²F/m, A = 5.10x10⁻³m², Vᵃᵇ = 125.00V, and d = 1.42x10⁻⁵m

Q = (8.85x10⁻¹²F/m)(5.10x10⁻³m²)(125.00V)/1.42x10⁻⁵m = 3.973x10⁻⁷C