explain: why doesn’t a convection cell form when the burner is turned off?

Answer: because she is pedalling at her maximum speed produced by the maximum force applied. At constant speed, acceleration is equal to zero.

Explanation:

Pedalling of bicycle involves application of force. The force applied produces circular motion to the tires which eventually transform into linear speed.

V = wr

Where V = linear speed

W = angular speed

r = radius.

Change in speed V will lead to acceleration or deceleration depending on increase or decrease in speed.

If she stops accelerating, then, she must have applied force that makes her pedalling at maximum speed. She is also maintaining this uniform (constant ) speed. After reaching her maximum speed.

At constant speed, acceleration = 0

Base on this explanation, even though she is still pedalling as fast as she can, which at constant speed, she will stop accelerating and her speed reaches a maximum value because she is pedalling at her applied maximum force.

Answer:

Resistive forces get bigger as the speed increases and eventually they reach the point where the pedalling forces become balanced and therefore there is no further acceleration.

Explanation:

Hope this helps:))

Answer:

neurons

Explanation:

Answer:

neutrons

Explanation:

Answer:

800km/s

Explanation:

Initial momentum = final momentum

the total momentum is zero, Before the release of the asteroid , but Superman and the asteroid are not moving.

So, according to the Conservation of momentum the total momentum when the astronaut is been thrown will equals to zero . Then we can say

Initial momentum = final momentum

Because the momentum of the Superman immediately the asteroid is been thrown is equal to the momentum of the asteroid

Momentum =(mass ×velocity)

the mass of the asteroid i= 1000M

Given velocity = 800 m/s,

momentum =(1000M)(800 m/s)

= 800,000M m/s.

to get the answer, we need to divide by Superman's mass, M, which gives his recoil velocity of 800,000 m/s.

But we're told to convert to km/ s

We know that 1m/s=0.001km/s

=(800,000M m/s)× (0.001km/s)

=800km/s

Therefore, his recoil speed (in km/s) is 800km/s

The current would be: I = V/R = 15 V / 300 Ω = 0.05 A. The resistance would be: R = V/I = 300 V / 0.02 A = 15,000 Ω. The new current would be 6 A. The new current would be 24 A.

1) Using Ohm's law, we can determine the current drawn by the circuit by dividing the voltage by the resistance. So, the current would be: I = V/R = 15 V / 300 Ω = 0.05 A.

2) Again, using Ohm's law, we can determine the resistance of the circuit by dividing the voltage by the current. So, the resistance would be: R = V/I = 300 V / 0.02 A = 15,000 Ω.

3) According to Ohm's law, if the resistance of a circuit is doubled without changing the voltage, the current will be halved. So, the new current would be 6 A.

4) Similarly, if the resistance of a circuit is halved without changing the voltage, the current will be doubled. So, the new current would be 24 A.

In summary, Ohm's law relates the current, voltage, and resistance in an electric circuit. By knowing any two of these values, we can calculate the third value using the formula I = V/R.

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Answer:

100 newton

Explanation:

newton third law of motion says to every action there is an always an equal and opposite reaction so the magnitude will stay equal but opposite direction

Answer:

- 100N is the answer of this question

You would be least likely to find an ionization nebula heated by hot young stars in an elliptical galaxy.

Elliptical galaxies are generally old and do not have much ongoing star formation, so they are less likely to have hot young stars that can ionize gas and create ionization nebulae. In contrast, spiral galaxies like the Milky Way often have regions of active star formation, where massive young stars heat up surrounding gas and create ionization nebulae. Irregular galaxies can also have ongoing star formation and thus may have ionization nebulae. However, elliptical galaxies are dominated by older, redder stars and lack the gas and dust necessary to form new stars, so they are not likely to host ionization nebulae.

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Answer:

C. Leadville has a higher elevation.

Explanation:

In those two cities depicted in the picture, one city being further west or east does not cause significant temperature change. (Too north or too south can change this but this is not what we are supposed to find.) Rules out A.

Latitude is basically where a city is on the map, either north or south, and they have the same latitude, so B doesn't make sense.

A difference between an average high and low does nothing to why it would be colder in one place over another.

C is the logical answer for this question. The elevation, or how high you're elevated, changes the temperature. The higher the elevation, the colder it becomes since you're more closer to the clouds, and the clouds are actually really cold. Did you know that? this is why we cannot breathe outside in airplanes, it is way too cold and not enough CO2 to survive.

(1) The angular velocity at position 1 of a uniform rod rotating freely around an axis can be determined.

(2) The velocity of the center of mass at position 2.

(1) To determine the angular velocity at position 1, we need to consider the conservation of angular momentum. Since the rod is rotating freely, there are no external torques acting on it.

The initial angular momentum is zero, and at position 1, the angular momentum is given by L = Iω, where I is the moment of inertia of the rod and ω is the angular velocity. By substituting the values of mass and length of the rod into the formula for moment of inertia, we can solve for ω.

(2) To calculate the velocity of the center of mass at position 2, relative to position 1 and at an angle theta, we can use the concept of angular velocity and linear velocity. The linear velocity of the center of mass is given by v = ωr, where ω is the angular velocity and r is the distance between the center of mass and the axis of rotation. By considering the given angle theta and the length of the rod, we can determine the distance r.

Substituting the value of ω calculated in part (1) into the formula, we can find the velocity of the center of mass at position 2, relative to position 1 and at angle theta.

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The statement that is false regarding redox reactions is B) A reaction can result in either oxidation or reduction, not both.

Redox (reduction-oxidation) reactions involve the transfer of electrons between species. In these reactions, one species undergoes oxidation (loses electrons) while another species undergoes reduction (gains electrons).

It is important to note that redox reactions always involve both oxidation and reduction occurring simultaneously. Therefore, statement B is false, as a reaction can result in both oxidation and reduction simultaneously.

Statement A is true because reactions involving elemental oxygen often serve as an oxidizing agent, causing other substances to undergo oxidation.

Statement C is true because reduction involves the gain of electrons, leading to a decrease in the oxidation state of a species. Statement D is true because oxidation involves the loss of electrons, resulting in an increase in the oxidation state of a species.

Therefore, the correct answer is B) A reaction can result in either oxidation or reduction, not both.

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Answer:

A. Is the bow made by hand?

Explanation:

Hope this helps.

Explanation:

a) What is the weight of the crate?

W = m*g = 60 kg *9.81 m/s^2 = 588.6 N

Sum of the forces in the vertical direction on the box (up is +) = F - W = 500 N - 588.6 N = -88.6 N

Since the forces do not add up to 0, then there is a net force on the crate which will cause the crate to accelerate.

b) F = m*a ==> a = F/m

a = -88.6 N / 60 kg = -1.48 m/s^2 (- means down since above we declared up as +)

c) Assume it starts from rest, vi = 0 m/s

Equation of motion in the vertical direction

h = h0 + v0*t + 1/2*a*t^2

h0 = 1.4 m

h = 0 m

v0 = 0 m/s

a = -1.48 m/s^2

0 = 1.4 m + 0 - 1/2* 1.48 m/s^2 * t^2

1.4 m = 1/2 * 1.48 m/s^2 * t^2

t = 1.38 s

d) vf = vi + a*t

vi = 0 m/s

vf = a*t = -1.48 m/s^2 * 1.38 s = -2.04 m/s

Answer:

D. All of the above

Explanation:

Because it's the most logical answer.

A key piece of evidence that leads astronomers to conclude that most galaxies include a supermassive black hole in the center is the observation of powerful energy emissions and specific signatures associated with active galactic nuclei (AGNs). AGNs are believed to be powered by accretion of matter onto supermassive black holes.

Astronomers have observed that certain galaxies emit tremendous amounts of energy, far beyond what can be explained by other known astrophysical processes. These active galaxies exhibit characteristics such as jets of high-energy particles, intense X-ray and gamma-ray emissions, and variations in brightness over time. These energetic phenomena are consistent with the presence of a supermassive black hole at the center of the galaxy, actively accreting matter and releasing enormous amounts of energy in the process. Additionally, studies of the dynamics of stars and gas in the central regions of galaxies have provided evidence for the existence of supermassive black holes. By measuring the orbital velocities of stars and gas near the galactic center, astronomers can infer the presence of a massive, compact object exerting gravitational influence on its surroundings.

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Given

The electric flux is

Radius of the sphere,

To find

a. The flux through a gaussian sphere with radius of 29.0 cm.

b. The magnitude of the charge

Explanation

a. Since the gaussian sphere covers the same charge so the electric flux through both the sphere will be same.

Thus the required flux is

b.

The magnitude of the charge is

Conclusion

a. The flux is

b. The charge is

Answer:

K.E is 90.625 J

Explanation:

Data:

Mass = m = 43.5kg

Distance = d = 1.3km = 1300 m

Time = t = 10.4 min = 624 sec

Accelaration = a or g = 9.8

Formula for kinrtic energy

K.E = 1/2mv²

Find velocity

V = d/t = 1300/624 = 2.0833333333333 m/s

Put values in formula

K.E = 1/2 (43.5)(2.084)² = 90.624999999995

Mark brainliest if you understand it

Answer:

C. She can increase the number of wire loops.

Explanation:

The more wire loops the more energy.

For a coil of wire, the magnetic field strength is increased by increasing the number of coils around the nail.

An electromagnet is a soft metal core shaped into a magnet by the passing the electric current through a coil surrounding it.

The end of the wire leading to the S is attached to the positive terminal of a battery. The end of the wire leading to the N is attached to the negative terminal of the battery. The current begins to flow. Current cant be changed to increase magnetic field strength, but the no of coils will definitely increase it.

Thus, To increase the strength of the electromagnet, Lisa can increase the number of wire loops.

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In a circuit, three wires form a junction. The current in one of the wires is either 7A or 17A, which is either the sum of the currents in the two-wire or the difference of current between two wires.

Electric current is the movement of charged particles (electrons or ions) through a current-carrying conductor, under the effect of potential difference induced between the ends of the conductor. It's measured in Ampere(A), which is the SI unit for current. Current in a circuit is measured using a device referred to as an ammeter.

When several conductors or semiconductors come into physical touch, the result is an electrical junction. Thermoelectricity junctions, metal-semiconductor junctions, and p-n junctions are a few different forms of electrical junctions.

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Answer:

Explanation:

F=ma

F in this case is the gravity acting on the 2kg object. Acceleration of gravity is 9.8 m/s^2. SF=ma, so

F = 2kg*(9.8 m/s^2) = 19.6 N

Now use this force to determine the mass of the object on the table:

F=ma

19.6 N (1N=kg*m/s^2) = m*(1.8 m/s^2)

m = 10.89 kg

The demand for a necessity such as electricity tends to be inelastic. Here's why:Inelastic demand is when changes in price don't affect the quantity demanded as much.

Necessities such as food, water, and electricity often have an inelastic demand, meaning that when the price of the product increases, the quantity demanded does not decrease as much.Explanation:For example, if the cost of electricity increased by 10%, a household might not be able to decrease its use of electricity as much, such as by 10%. The amount of electricity that a household uses might not be affected by price changes because it's a necessity.A vertical demand curve implies that a change in price results in no change in quantity demanded.

Unit elastic refers to a change in price that results in a proportional change in quantity demanded.D elastic refers to the degree of price sensitivity. Demand is said to be elastic when a price change causes a substantial change in demand.

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Answer:

Tuning a piano is the process of adjusting the tension of its strings, thereby altering their pitch, or frequency of vibration, by slightly turning the tuning pins to which they're attached, so that each string sounds pleasingly in harmony with every other string.

Explanation:

Find an energy is E =mgh, so E = 45*10*19=8550j

A star is considered circumpolar if it remains above the horizon throughout the entire night. The greatest distance that a star can be from Polaris, the North Star, and still be circumpolar is 50°.

Circumpolar stars are those that do not set below the horizon but instead appear to revolve around the celestial pole. In the northern hemisphere, Polaris serves as the North Star, located very close to the celestial north pole.

For a star to be circumpolar as seen from Philadelphia (latitude 40.0°), it must remain above the horizon at all times during the night.

The distance between Polaris and the celestial pole is equivalent to the observer's latitude. In this case, since the latitude of Philadelphia is 40.0°, any star within 40.0° of Polaris will be circumpolar.

Therefore, the greatest distance a star can be from Polaris and still be circumpolar is 40.0° + 10.0° (as the North Star is approximately 10.0° away from the celestial pole), giving a total of 50.0°.

Any star within this range, up to 50.0° from Polaris, will never dip below the horizon and will remain visible throughout the entire night as a circumpolar star.

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Answer:

Explanation:

Using the formula for heart capacity;

Q = mcΔt

m is the mass = 150g = 0.15kg

initial temperature = 22°C

Quantity of heat = 3240J = 3.24kJ

specific heat capacity of ethanol = 2.57 [kJ/kg K]

Substitute and get the final temperature

3.240 = 0.15(2.57)(T - 22)

3.240 = 0.3855(T-22)

3.240/0.3855 = T - 22

8.405 = T - 22

T = 22+8.405

T = 30.405°C

Hence the final temperature of the ethanol if 3240 J was needed to raise the temperature of the ethanol is 30.405°C

Answer: A mixture

Explanation:

A mixture is where 2 or more substances are physically combined, and where you can know what each substance is

Answer: Mixture

Mixture is made up of two or more different substances, which are mixed but not combined chemically.

Explanation:

Hope this helps =)

Answer:

1) To find the volume of the wood block, divide the mass by the density:

Volume = 583.3 g / 2.7 g/cm³

Volume = 216.24 cm³

2) To find the density of the butter, divide the mass by the volume:

Density = 319 g / 350 cm³

Density = 0.9114 g/cm³

Explanation:

Answer:

W = 19.845 J

Explanation:

Work is defined as W = Fdcos\(\theta\), where F is the force exerted and d is the distance. Because the direction the ball is falling is the same direction as the force itself, \(\theta\) = 0 deg, and since cos(0) = 1, this equation is equivalent to W = Fd. In this case, the force exerted is the weight force, which is equivalent to m * g. Substituting you get:

W = mgd = 0.810 kg * 9.8 m/s^2 * 2.5m

W = 19.845 J

Answer:

4. All of the above

Explanation:

The purpose of striking the ball in a volleyball game:

From the serve you could state that you need to place the ball in motion.

When returning a shot of, you normally want to change the direction of the ball's motion.

During a dropshot, you purposely want to slow down the ball's motion.

The correct answer must be all of the above.

The displacement of the pendulum is 0.815 m.

Mass of the pendulum, m = 25 kg

Length of the pendulum, l = 0.75 m

Distance moved by the pendulum, x = 0.25 m

Therefore, acceleration of the pendulum,

a = -(g/l) x   the negative sign implies the restoring force.

a = -(9.8/0.75) 0.25

a = -3.26 m/s²

Time period of the pendulum = 2 s

Angular frequency, ω = 2\(\pi\)/T

ω = 2 x 3.14/2

ω = 2 s⁻¹

Displacement,

x' = -(a/ω²)

x' = 3.26/4

x' = 0.815 m

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Answer:

m = FpCos0 / a

Explanation:

it just is

A box of mass m is pulled at an angle θ by a force Fp along a frictionless surface. The box travels to the right with acceleration a

What is the mass m of the box?

Answer: m = FpCos0/a

Answer:

The change in momentum for the bug and the car will be equal, impulses will be equal in opposite directions and the bug will have a greater acceleration compared to the car, because it has a smaller mass.

Explanation:

Hope this helps..