According to the passage, why don’t sharks sink in the water?
A Sharks don’t sink because they eat seals and sea lions.
B Sharks don’t sink because their liver is filled with oil.
C Sharks don’t sink because the water is polluted.
D Sharks don’t sink because they are very light

please help me for 20 points

Answer: Pa=Pv

Explanation:

Khan academy

Amos runs up a flight of stairs with a total change in energy ΔEA. Vanessa exerts double the amount of energy in twice the time.

How does Amos’s power output, PA, compare with Vanessa’s power output, Pv?

Answer: Pa=Pv

Answer:A

Explanation:

The wavelength of the sound wave will be 3 meters.

The wavelength of any wave is defined as the distance between two max adjacent amplitudes, or the distance between two successive troughs or crest.

Now it is given that:

Distance =9 meters

time = 3 seconds

pitch=1/3 seconds

The velocity of  the sound will be

[tex]V=\dfrac{d}{t}=\dfrac{9}{3}=3\ \frac{m}{s}[/tex]

Now from the question the wavelength of the sound wave if the velocity of the wave remains constant but the pitch is tripled

so  [tex]f=3\times \dfrac{1}{3}=1 herts[/tex]

Now the velocity of the sound will be

[tex]v=f\times \lambda[/tex]

[tex]\lambda=\dfrac{v}{f}=\dfrac{3}{1}=3\ m[/tex]

Thus the wavelength of the sound wave will be 3 meters.

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Answer:

Density = 0.243 g/cm³

Explanation:

Volume of cork = 23.5 cm³

Mass = 5.7 g

To find the density of the cork;

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 formula;

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

Substituting into the formula, we have;

Density = 5.7/23.5

Density = 0.243 g/cm³

Both are false..........

Answer:

A) As her parachute opens, her acceleration is upwards.

Explanation:

The acceleration is the rate of change of the velocity.

Thus, if you have positive velocity and positive acceleration, your velocity increases

If you have positive velocity and negative acceleration, then your velocity decreases.

(The opposite happens when you have negative velocity).

Now, when the skydiver is falling, her velocity is downwards.

When she opens her parachute, her velocity downwards decreases.

This means that when she opens her parachute, she will have an acceleration in the opposite direction to her velocity, then at this point her acceleration is upwards.

We can conclude that the correct option is:

A) As her parachute opens, her acceleration is upwards.

Answer: A is the correct answer :)

Explanation:

Answer:

Fossil fuels store energy from the sun as

Answer:

light to chemichal

Explanation:

Answer:

Are similar in pattern

Explanation:

edge 2021

hope it is helpful to you

Answer:

As global population a.) increases food production must a.) increase.

Example:

More people means more food must be produced.

Answer:

960W

Explanation:

v=R×I

v=60ohm.4A=240v

p=VI

p=240v.4A

p=960W

The power of a hair dryer with a current of 4 A and a resistance of 60 ohms is 960 W.

The amount of work completed in a given amount of time. Watt (W), which is derived from joules per second (J/s), is the SI unit of power. Horsepower (hp), which is roughly equivalent to 745.7 watts, is a unit of measurement sometimes used to describe the power of motor vehicles and other devices.

Given in the question a hair dryer with a current of 4 A and a resistance of 60 ohms power, p

Voltage, v=R×I

v=60 ohm.4 A=240 v

power, p=VI

p=240 v.4 A

p=960 W

The power of a hair dryer with a current of 4 A and a resistance of 60 ohms is 960 W.

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Answer:

9800 N

Explanation:

applying,

W = Fd.................. Equation 1

Where W = work done by the engine, F = Force exterted to lift the beam, d = distance.

make F the subject of the equation

F = W/d............... Equation 2

From the question,

Given: W = 1421000 J, d = 145 meters.

Substitute these values into equation 2

F = 1421000/145

F = 9800 N

Answer:

A light wave travels through the vacuum of space

Explanation:

A light wave cannot be a matter wave because a matter wave is made up of

atoms while light wave is a form of radiation (electromagnetic). A matter wave requires a medium to travel while a light wave do not require medium to travel. Since light wave is a form of radiation, light can travel in vacuum.

Hence, the correct answer is A light wave travels through the vacuum of space

Answer: Earthquakes and Volcanic eruptions

Explanation:

You did not attach a picture however, this should be the correct answer.

Mid-oceanic ridge plate  boundaries such as the Mid-Atlantic Ridge form as a result of plate separating at the boundary. This leads to earthquakes due to the forces of tension acting on the plates.

When this happens, the mantle is exposed and therefore there will be volcanic eruptions as the lava comes to the surface as magma. When this magma cools it creates new seafloors and underwater mountains.

Answer:

-0.6 m/s^2

Explanation:

a = change in velocity / time

change in velocity = 50 m/s - 20 m/s = 30 m/s

time = 50 s

30 m/s / 50s

= 0.6 m/s^2

because it is decelarating, it will be -0.6 m/s^2

Answer:

Acceleration is the name we give to any process where the velocity changes. Since velocity is a speed and a direction, there are only two ways for you to accelerate: change your speed or change your direction—or change both.

Answer:

the answer is c

Explanation:

i did the test

Answer:

a) El piñón debe tener 20 dientes.

b) La bicicleta avanza aproximadamente 1,759 metros por cada pedaleada completa.

Explanation:

a) El plato es el engranaje más grande que forma parte del sistema de transmisión, acompañando a la cadena y el piñón integrado a la rueda trasera. Asumiendo que no existen pérdidas por fricción seca y que las condiciones de lubricación del sistema de transmisión son óptimas tal que las pérdidas de potencia son despreciables. Además, supongamos que la bicicleta viaja a velocidad constante, entonces tenemos la siguiente identidad mediante las definiciones de trabajo y potencia:

[tex]T_{P}\cdot \omega_{P} = T_{p}\cdot \omega_{p}[/tex] (1)

Donde:

[tex]T_{P}[/tex] - Torque del plato, en newton-metros.

[tex]T_{p}[/tex] - Torque del piñón, en newton-metros.

[tex]\omega_{p}[/tex] - Rapidez angular del piñón, en radianes por segundo.

[tex]\omega_{P}[/tex] - Rapidez angular del plato, en radianes por segundo.

Sabiendo el hecho que tanto el plato y el piñón experimenta la misma velocidad tangencial, podemos simplificar (1) como sigue:

[tex]\frac{T_{P}}{R_{P}} = \frac{T_{p}}{R_{p}}[/tex] (1b)

Puesto que el radio de cada elemento y el número de dientes son, por separado, directamente proporcionales al número de dientes, modificamos (1b) así y tenemos la siguiente identidad, la cual equivale a su vez a la razón de desarrollo:

[tex]\frac{T_{P}}{T_{p}} = \frac{N_{P}}{N_{p}} = \frac{R_{P}}{R_{p}} = \frac{\omega_{p}}{\omega_{P}}[/tex] (1c)

Donde:

[tex]N_{p}[/tex] - Número de dientes del piñón, sin unidad.

[tex]N_{P}[/tex] - Número de dientes del plato, sin unidad.

Si tenemos que [tex]r = 1,4[/tex] y [tex]N_{P} = 28[/tex], entonces tenemos que el número de dientes del piñón es:

[tex]r = \frac{N_{P}}{N_{p}}[/tex]

[tex]N_{p} = \frac{N_{P}}{r}[/tex]

[tex]N_{p} = \frac{28}{1,4}[/tex]

[tex]N_{p} = 20[/tex]

El piñón debe tener 20 dientes.

b) De acuerdo con la relación de desarrollo, por cada revolución realizada por el plato, el piñón realiza 1,4 revoluciones. Entonces, el avance realizado por la rueda trasera ([tex]s[/tex]), en metros, es igual al productor de la relación de desarrollo y la circunferencia de la rueda, es decir:

[tex]s = r\cdot 2\pi\cdot R[/tex] (1)

Donde [tex]R[/tex] es el radio de la rueda trasera, en metros.

Si conocemos que [tex]r = 1,4[/tex] y [tex]R = 0,2\,m[/tex], entonces el avance realizado por la rueda trasera es:

[tex]s = r\cdot 2\pi\cdot R[/tex]

[tex]s = (1,4)\cdot (2\pi)\cdot (0,2\,m)[/tex]

[tex]s \approx 1,759 \,m[/tex]

La bicicleta avanza aproximadamente 1,759 metros por cada pedaleada completa.

Answer:

The slope of a velocity graph represents the acceleration of the object. So, the value of the slope at a particular time represents the acceleration of the object at that instant.

Answer:

The slope of a velocity graph represents the acceleration of the object.

Explanation:

So, the value of the slope at a particular time represents the acceleration of the object at that instant.

Answer:

option one

Explanation:

equilibrium is used to describe the point in which something meets in this case the temperature of an object

Answer:

Milk Lactometer

Milk Lactometer: A lactometer is an instrument that is used to check for the purity of milk by measuring its density.

lactometer is used to determine the purity of milk

hope it is helpful to you

Answer:

B

Explanation:

First narrow answers to CIRCULAR motion.

Only A and B have circular motion.

Second look at the keyword UNIFORM. A swing does not have uniform motion because it will accelerate due to gravity and have the most velocity at the bottom of the swing.

Therefore, it must be B.

Answer:

A

Explanation:

The Reaction rate is going down which is why its at 0 And the concetration line is going up which means increasing,

Answer:

The voltage across light bulb 1 and light bulb 2 is the the same i.e V

Explanation:

In a parallel circuit, the Voltage is same across all the components of the circuit and the current flowing through each component is added to get the total current across the circuit.

Let us say, the voltage across the circuit is V. The voltage across light bulb 1 and light bulb 2 is the the same i.e V

Answer:

In this section, we elaborate and extend the result we derived in Potential Energy of a System, where we re-wrote the work-energy theorem in terms of the change in the kinetic and potential energies of a particle. This will lead us to a discussion of the important principle of the conservation of mechanical energy. As you continue to examine other topics in physics, in later chapters of this book, you will see how this conservation law is generalized to encompass other types of energy and energy transfers. The last section of this chapter provides a preview.

The terms ‘conserved quantity’ and ‘conservation law’ have specific, scientific meanings in physics, which are different from the everyday meanings associated with the use of these words. (The same comment is also true about the scientific and everyday uses of the word ‘work.’) In everyday usage, you could conserve water by not using it, or by using less of it, or by re-using it. Water is composed of molecules consisting of two atoms of hydrogen and one of oxygen. Bring these atoms together to form a molecule and you create water; dissociate the atoms in such a molecule and you destroy water. However, in scientific usage, a conserved quantity for a system stays constant, changes by a definite amount that is transferred to other systems, and/or is converted into other forms of that quantity. A conserved quantity, in the scientific sense, can be transformed, but not strictly created or destroyed. Thus, there is no physical law of conservation of water.

Systems with a Single Particle or Object

We first consider a system with a single particle or object. Returning to our development of (Figure), recall that we first separated all the forces acting on a particle into conservative and non-conservative types, and wrote the work done by each type of force as a separate term in the work-energy theorem. We then replaced the work done by the conservative forces by the change in the potential energy of the particle, combining it with the change in the particle’s kinetic energy to get (Figure). Now, we write this equation without the middle step and define the sum of the kinetic and potential energies, K+U=E; to be the mechanical energy of the particle