Una sirena que emite un sonido de f=100Hz se mueve alejandose de un observador en reposo y dirigiendose hacia un acantilado con velocidad constante de v1=20 m/s.

Answer:

V = 0.01(R₁ + R₂)

Explanation:

From Ohm's law, the voltage V across a resistor with resistance R and a current I passing through it is given by

V = IR

If we have two resistances, R₁ and R₂ in series, the total resistance R is the sum of their resistances.

So, R = R₁ + R₂

Now, if the current in the circuit is 0.01 A, the voltage V is

V = IR

V = 0.01R

Substituting R = R₁ + R₂ into the equation for V, we have

V = 0.01(R₁ + R₂)

So, the voltage in two series resistors with current 0.01 A is

V = 0.01(R₁ + R₂)

Light bends away from the normal, because it's moving from higher to lower refractive index.

Same bend-direction as when it goes from water into air.

Show us the experiment then

Answer: In the direction of the first car.

Explanation:

Let the initial velocity of the first car be equal to U1 and the initial velocity of the second car be equal to U2

Given that the car is travelling with a positive velocity, and after it collides with another car moving with a negative velocity, the momentum before collision will be

M1U1 - M2U2

If the first car is still moving with a positive velocity, the second car will also be moving in the direction of the first car if the collision is inelastic collision.

Therefore, the direction of the second car will be positive direction if the collision is inelastic collision.

Answer:

86.17m/s

Explanation:

Since the motion is of constant acceleration, we can use one of the equations of motion as follows;

v² = u² + 2as

Where;

v = final velocity of the airplane

u = initial velocity of the airplane

s = distance covered by the plane

a = acceleration

From the question,

u = 15m/s

s = 600m

a = 6m/s²

Substitute these values into the equation above as follows;

v² = 15² + 2(6)(600)

v² = 225 + 7200

v² = 7425

v = √7425

v  = 86.17m/s

Therefore, the final velocity of the airplane is 86.17m/s

Answer:

I = 2.61 A

Explanation:

It is given that,

Power of a toaster is 300 watts

It is plugged into an outlet with a voltage of 115 volts

We need to find the current in the toaster's circuit.

The electrical power is given by the formula as follows :

P = V I

I is electric current

[tex]I=\dfrac{P}{V}\\\\I=\dfrac{300}{115}\\\\I=2.61\ A[/tex]

So, 2.61 A of current is in the toaster's circuit.

Answer: D.

2.61 amps

Explanation: edmentum

Explanation:

[tex]a = \frac{change \: in \: velocity}{change \: in \: time} [/tex]

[tex]a = \frac{v - u}{t} [/tex]

[tex]v = 7 {ms}^{ - 1} [/tex]

[tex]u = 15 {ms}^{ - 1} [/tex]

[tex]t = 3 \: seconds[/tex]

[tex]a = \frac{7 - 15}{3} [/tex]

[tex]a = \frac{ - 8}{3} [/tex]

[tex]a = - 2.67 \: {ms}^{ - 2} [/tex]

Answer: The final Velocity, V, of the car is 7.9m/s

Explanation:

Given the following :

Toy car starts from rest, therefore,

Initial Velocity (u) = 0

Acceleration (a) = 1.5m/s^2 E for time, t = 5.25s

Final velocity (V) of the car =?

Using the motion equation:

v = u + at

Where v = final Velocity

u = Initial Velocity

a = acceleration

t = time

v = 0 + 1.5(5.25)

v = 0 + 7.875

v = 7.875m/s

v = 7.9m/s

Answer:

  D. 3.0 × 10^-6 m

Explanation:

Wavelength is found by dividing the speed of light by the frequency:

  λ = c/f = (3·10^8 m/s)/(1.0·10^14 Hz) = 3.0·10^-6 m

Answer:

By nuclear fission

Explanation:

The sun generates enormous energy through the process of nuclear fusion.

The core or the innermost part of the sun is characterized by high temperature and pressure. These two factors cause the separation of nuclei from electrons and the fusion of hydrogen nuclei to form a  helium atom.

During the fusion process, energy is released.

Answer:

Joule

Explanation:

As any unit of energy (kinetic, potential, etc.), the gravitational potential energy has SI units of Joule. This s the work done by a force of 1 Newton to displace an object 1 meter in the direction of application of the force.

Answer:

decrease

Explanation:

as the mass of the cart increase the acceleration of the cart decrease

Answer:

Explanation:

Kinetic energy is 1/2mv²

where m is the mass of the object

v is the velocity

From the question

m = 200kg

v = 2.7m/s

Kinetic energy is

1/2 × 200 × 2.7²

= 729 Joules

Hope this helps you

Answer: B. Carbon dioxide and water

Explanation: Combustion simply refers to burning. A combustion reaction may thus be explained as a chemical process which involves the reaction between a substance and an oxidizer usually oxygen gas. The combustion reaction in most cases involves the reaction between hydrocarbons which are combustible compounds and oxygen gas. The reaction between the combustible compound and oxygen gas is then followed by the release of energy, with the product being carbondioxid and water. Below is an example of combustion reaction.

Combustion the Methane CH4.

Here, CH4 reacts with oxygen gas(O2) to produce carbondioxide and water.

CH4 + 2O2 ------> CO2 + 2H2O

Answer:

Correct answer B

Explanation:

Just took quiz

Answer:

a. No. The overall loudness is not proportional to the number of speakers.

b. No, it will not sound 4 times louder.

Explanation:

a. Loudness is the quality of how loud or soft the sound is. Since loudness is proportional to intensity and intensity proportional to the amplitude of the sound, the overall loudness of the sound would not be proportional to the number of speakers.

Since the sound from each speakers adds by superposition, their phases might be different but their amplitudes the same. So, the resultant wave from the four speakers has the same amplitude as the wave from one speaker. And, since loudness is proportional to amplitude, the loudness of the resultant wave is equal to the loudness of each individual speaker.

So, the loudness is not proportional to the number of speakers.

b. No, it will not sound 4 times louder.

This is because loudness is a function of amplitude.

Since the devices are identical and playing the same sound, their amplitudes are the same. They will thus add by superposition to generate a resultant wave which has an amplitude the same as each individual wave.

Since the amplitude of the resultant wave is the same and not an addition of each individual amplitude, the resultant wave does not sound 4 times louder.

Answer:

n = 3.1x10¹²

Explanation:

To find the number of electrons we need to find first the charge (q):

[tex] I = \frac{q}{\Delta t} \rightarrow q = I*\Delta t [/tex]    (1)

Where:

I: is the electric current = 0.59 A

t: is the time

The time t is equal to:

[tex]v = \frac{\Delta x}{\Delta t} \rightarrow \Delta t = \frac{\Delta x}{v}[/tex]   (2)

Where:

x: is the displacement

v: is the average speed = 2.998x10⁸ m/s

The displacement is equal to the perimeter of the circumference:

[tex] \Delta x = 2\pi*r = \pi*d [/tex]     (3)

Where d is the diameter = 80.0 m

By entering equations (2) and (3) into (1) we have:

[tex]q = I*\Delta t = I*\frac{\Delta x}{v} = \frac{I\pi d}{v} = \frac{0.59 A*\pi*80.0 m}{2.99 \cdot 10^{8} m/s} = 4.96 \cdot 10^{-7} C[/tex]      

Now, the number of electrons (n) is given by:

[tex] n = \frac{q}{e} [/tex]

Where e is the electron's charge = 1.6x10⁻¹⁹ C  

[tex] n = \frac{q}{e} = \frac{4.96 \cdot 10^{-7} C}{1.6 \cdot 10^{-19} C} = 3.1 \cdot 10^{12} [/tex]

Therefore, the number of electrons in the beam is 3.1x10¹².

I hope it helps you!

Answer:

b

Explanation:

Given that,

Weight = 0.75 N

Acceleration due to gravity = 9.81 m/s²

Density of water = 1 g/ml

We need to calculate the volume of water

Using formula of weight

[tex]W=mg[/tex]

[tex]W=\rho Vg[/tex]

[tex]mg=\rho\times V\times g[/tex]

Where, V = volume

g = acceleration

m = mass

Put the value into the formula

[tex]0.076\times 9.8\times10^3=1\times V\times9.8[/tex]

[tex]V= \dfrac{0.076\times 9.8\times10^3}{1\times9.8}[/tex]

[tex]V=76\ ml[/tex]

Hence, The volume of water is 76 mL.

Answer:

76.5mL

Explanation:

w = mg

0.75N = m * 9.81

m = 0.75 / 9.81 = 0.0765 kg

The mass in grams is 0.0765 * 1000 = 76.5g

At a density of 1 g/mL,

76.5g ÷ 1g/ml = 76.5mL

Answer: The image is at a distance of 24 cm on the right of the lens, it will be an inverted, real image and has a height of 7 cm.

Explanation: To determine the position of the image of the object, use the Lens Equation, which is described by:

[tex]\frac{1}{f} = \frac{1}{u} +\frac{1}{v}[/tex]

where

f is focal length;

u is distance of the object from the lens;

v is distance of the image of the pbject from the lens;

Calculating the position of the image will be:

[tex]\frac{1}{v} =\frac{1}{f} - \frac{1}{u}[/tex]

[tex]\frac{1}{v} = \frac{1}{8} - \frac{1}{12}[/tex]

[tex]\frac{1}{v} = \frac{1}{24}[/tex]

v = 24 cm

Note that the distance of the image from the lens is positive. This means that the formed image is positioned at the right of the lens and is inverted.

For the height of the image, it can be used the Magnification (M) of an image:

M = [tex]\frac{h_{i}}{h_{o}} = \frac{v}{u}[/tex]

where:

[tex]h_{i}[/tex] is the height of the image

[tex]h_{o}[/tex] is the height of the object

For this image:

[tex]\frac{h_{i}}{3.5} = \frac{24}{12}[/tex]

[tex]h_{i} =[/tex] 2 * 3.5

[tex]h_{i}[/tex] = 7 cm

The image formed for this lens is 24 cm on the right of the lens, inverted related to the object and has height of 7 cm.

This question is incomplete because the options are missing; here is the complete question:

Study the image of the Earth's layer which statement correctly compares the thicknesses of earths layers

A. Earth’s mantle is thinner than its oceanic crust.

B. Earth’s outer core is thicker than its mantle.

C. Earth’s continental crust is thicker than its lithosphere.

D. Earth’s lithosphere is thinner than its asthenosphere.

The answer to this question is D. Earth’s lithosphere is thinner than its asthenosphere.

Explanation:

The image shows the different layers that are part of Earth, as well as the thickness of each layer, in kilometers. In this, the thickest layer is the Mantle that is almost 2900 kilometers; this is followed in thickness by the outer and the inner core.

Additionally, other layers such as the continental/oceanic crust, the asthenosphere, and the lithosphere that are near the surface are thinner. About this, it can be concluded the lithosphere is thinner than the asthenosphere because the lithosphere has a thickness of 100 km, while the asthenosphere thickness is 660km. This makes option D the correct.

Explanation:

If Team A is on the left, B is on the right

if the force is constant, it means that the effort applied is equal.

So Team B is pulling 5000N to the right.

Answer:

C.25km

Explanation:

half of 50 is 25.

Answer:

C. 25 km

Explanation:

The train moves 50 kilometers in 1 hour.

In 0.5 hours, the train will travel 50(0.5) = 25 kilometers.

Answer:

15 m

Explanation:

The distance travelled by the driver before they put their foot on the brakes can be derived from the stopping distance and the braking distance of the car.

d = stopping distance - braking distance

Stopping distance = 50 m

Braking distance = 35 m

d = 50 - 35 m

d = 15 m

The distance travelled by the driver before they put their foot on the brakes is 15 m

Answer:

1.01 W/m

Explanation:

diameter of the pipe d = 30 mm = 0.03 m

radius of the pipe r = d/2 = 0.015 m

external air temperature Ta = 20 °C

temperature of pipe wall Tw = 150 °C

convection coefficient at outer tube surface h = 11 W/m^2-K

From the above, we assumed that the pipe wall and the oil are in thermal equilibrium.

area of the pipe per unit length A = [tex]\pi r ^{2}[/tex] = [tex]7.069*10^{-4}[/tex] m^2/m

convectional heat loss Q = Ah(Tw - Ta)

Q = 7.069 x 10^-4 x 11 x (150 - 20)

Q = 7.069 x 10^-4 x 11 x 130 = 1.01 W/m

The heat loss per unit length of tube should be considered as the 1.01 W/m.

Since

diameter of the pipe d = 30 mm = 0.03 m

radius of the pipe r = d/2 = 0.015 m

external air temperature Ta = 20 °C

temperature of pipe wall Tw = 150 °C

convection coefficient at outer tube surface h = 11 W/m^2-K

Now

area of the pipe per unit length A should be

= πr^2

 = 7.069*10^-4 m^2/m

Now

convectional heat loss Q = Ah(Tw - Ta)

Q = 7.069 x 10^-4 x 11 x (150 - 20)

Q = 7.069 x 10^-4 x 11 x 130

= 1.01 W/m

hence, The heat loss per unit length of tube should be considered as the 1.01 W/m.

Learn more about heat here: https://brainly.com/question/15170783

Answer:

D

Explanation:

Damage to the sun is not a negative effect of the way we use science because we can't affect the sun due to its long distance from us.

Humans negatively affected environment by using science because with the help of science we made new technologies which leads to Climate Change, Pollution and Overuse of resources.

So we can conclude that option D is the right answer.

Learn more about science here: https://brainly.com/question/17216882

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Answer:

Option A - Because of Newton's first law of motion

Explanation:

This is as a result of Newton's first law of motion.

Newton's first law of motion which is also referred to as the law of inertia states that; an object at rest will remain at rest and an object in motion will remain in motion with the same speed and in the same direction unless it's acted upon by an unbalanced force.

In this question, the car is at rest and it doesn't move because the upward force of the car is balanced by the downward pull of gravity. It can only move when an external force is applied to it. This fulfills Newton's first law of motion.

Copper is a reddish orange, soft metal with a bright metallic luster. It is an excellent conductor of heat and electricity. Copper surfaces when exposed to air gradually turns to a dull, brownish color.

the answer is radioactive processes within the Earth.

Answer:

Radioactive processes within the Earth.

Explanation:

many of Earth’s heat is constantly generated by the decay of radioactive isotopes, such as potassium-40 and thorium-232.

Answer:

1120 N

Explanation:

The velocity with which he hits the water can be found with kinematics:

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (-9.8 m/s²) (-9.00 m)

v = -13.3 m/s

Or it can be found with conservation of energy.

PE = KE

mgh = ½ mv²

v = √(2gh)

v = √(2 × -9.8 m/s² × -9.00 m)

v = -13.3 m/s

Sum of forces on the diver after he hits the water:

∑F = ma

F − mg = m Δv/Δt

F − (74.0 kg) (9.8 m/s²) = (74.0 kg) (0 m/s − (-13.3 m/s)) / (2.50 s)

F = 1120 N