Can someone please Help me

Answer:

3200 seconds

Explanation:

If he ran at 3 m/s for 28.5 seconds, he would have run 85.5 meters

29 seconds would be 87 meters run not 9.5 km

Answer;  Ultrasonic waves (sounds having frequency greater than 20,000 Hz) are used in sonar because: ... Ultrasonic waves can penetrate water to long distances (because of their high frequency and very short wavelength), but ordinary sound waves or infrasonic waves cannot penetrate water to such long distances.

Answer:

Ultrasonic waves (sounds having frequency greater than 20,000 Hz) are used in sonar because: ... Ultrasonic waves can penetrate water to long distances (because of their high frequency and very short wavelength), but ordinary sound waves or infrasonic waves cannot penetrate water to such long distances

Explanation:

Answer:

120 miles per hour.

Explanation:

We need to find the time it takes my parents to drive home from the cottage. Since my father drives at 60 miles per hour, and the cottage is 240 miles from our home, and distance = speed × time. So, time = distance/speed = 240 mi/60 mi/h = 4 h.

So, it will take my father 4 hours to drive home from the cottage.

Since I have 2 hours to prepare for the party, the time left for me to drive to the cottage is 4 - 2 hrs = 2 hrs.

So, I'm supposed to drive to the cottage in at most 2 hours.

The speed at which I must drive in this time period is thus,  speed = distance/time = 240 miles/2 hours = 120 miles per hour.

So, I must drive at a minimum speed of 120 miles per hour.

Answer:

At low frequencies, external electric and magnetic fields induce small circulating currents within the body. ... The main effect of radiofrequency electromagnetic fields is heating of body tissues. There is no doubt that short-term exposure to very high levels of electromagnetic fields can be harmful to health.

Answer:

the answer is A the one that has the green ball as particles

Explanation:

The second image showing an electromagnet is an example of the electromagnetic force in action therefore the correct option is B

It is a type of force that occur between electrically charged particles. The electromagnetic force is the combination of all the electrical and magnetic forces generated from any charged particle,

These electromagnetic forces either be attractive or repulsive.

The force generated from a simple bar magnet is an example of the electromagnative force, hence the correct option is B

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Answer:

The gravitational potential energy is 2,750 Joules

Explanation:

Given the following data;

Mass of brick = 1kg

Height of Eiffel Tower = 275m

Potential energy can be defined as the energy possessed by an object due to its position.

Mathematically, potential energy is;

[tex] P = mgh[/tex]

Also, we know acceleration due to gravity = 10m/s2

[tex] P = mgh[/tex]

[tex] P = 1 * 275 * 10 [/tex]

P = 2750 Joules.

Hence, the gravitational potential energy the brick acquired is 2750 Joules.

Answer:

с

creates its own light, which is blocked by the Sun during an eclipse.

Explanation:

might not be right but its what i remember

Given :

An ant is crawling along a yardstick that is pointed with the 0-inch mark to the east and the 36-inch mark to the west.

It starts at the 14-inch mark, crawls to the 20-inch mark, then moves to the 16-inch mark.

To Find :

The total distance the ant traveled.

Solution :

Total distance travelled by ant = (distance between 14 and 20 inch mark) +

                                                      (distance between 20 and 16 inch mark)

Total distance = (20-14 ) + ( 20-16) = 6 + 4 = 10 inch.

Therefore, total distance the ant traveled is 10 inch.

Hence, this is the required solution.

Answer:

1200

Explanation:

Force = Mass x Acceleration

Answer:

[tex]\boxed {\tt 1,200 \ Newtons }[/tex]

Explanation:

Force can be found by multiplying the mass by the acceleration.

[tex]F=m*a[/tex]

The mass is 300 kilograms.

The acceleration is 4 meters per second squared.

[tex]m= 300 \ kg\\a= 4 \ m/s^2[/tex]

Substitute the values into the formula.

[tex]F= 300 \ kg * 4 \ m/s^2[/tex]

Multiply.

[tex]F= 1200 \ kg * m/s^2[/tex]

1 Newton is equal to 1 kilograms meters per second squared, so our current answer of 1200 kg m/s² is equal to 1200 Newtons.

[tex]F= 1200 \ N[/tex]

The force needed is 1,200 Newtons.

Answer:

the words

Explanation:

Answer:

Pressing the brake pedal

Explanation:

Decelerate sounds a lot like the word accelerate, but we know that the speed is decreasing, so it would have to be going down, getting slower, so whichever sounds like a good example of speed decreasing should be a good answer!

Answer:

The wave velocity and the wavelength are related to the wave's frequency and period by vw=λT or vw=fλ. The time for one complete wave cycle is the period T. The number of waves per unit time is the frequency ƒ. The wave frequency and the period are inversely related to one another.

Explanation:

Answer:

1 : an object occupying a central position especially : an adornment in the center of a table. 2 : one that is of central importance or interest in a larger whole the centerpiece of a political agenda.

Explanation:

Answer:

C. Move the magnetized nail back and forth within the wire coil to induce an electric current in the wire.

Hope this helps.

Answer:

The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. 60 km/h to the north).

Answer: if this is the same question I think it’s 24

Explanation:

Answer:

7357.5N

Explanation:

Weight is the force used to pull a mass of object towards the centre of the Earth. The force is 9.81 N/kg.

so, Weight = mass × 9.81

the weight of the space probe should be: 750 × 9.81 = 7357.5 N

Answer:

7350N

Explanation:

Data

m-750kg

g-9.8

W=mg

=750 x 9.8

=7350N

Answer:

A, Bohr's model

Explanation:

Took the quiz, hope it's right for you.

(The other three did have something to do with it they just didn't create that specific model)

The model of the atom that has electrons traveling in specific paths around the nucleus is Rutherford's model.

Therefore, the correct answer is option B

J. J Thomson proposed that the atom is a sphere of positively charged matter in which negatively charged electron are embedded.

In Rutherford's model of atomic structure, the electrons moves in orbits by electrostatic attraction to the positively charged nucleus.

According to Dalton's atomic theory, atom were indestructible and indivisible  solid particle.

Bohr's model made assumption that electron can only exist in circular orbits of definite quantum energy.  

According to the question, the model of the atom that has electrons traveling in specific paths around the nucleus is Rutherford's model.

Therefore, the correct answer is option B

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Answer:

I'm pretty sure that the answer is A

Answer:

synthesis and combustion

double replacement

single replacement

decomposition only

in that exact order edge 2020

The presented reactions are:

S + O₂ ⇒ SO₂    Synthesis or combination

CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl   Double displacement

Zn + CuSO₄ = Cu + ZnSO₄   Single displacement

2 Na₂O = 4 Na + O₂   Decomposition

Let's consider and classify the following reactions.

S + O₂ ⇒ SO₂

This is a synthesis or combination reaction. 2 compounds combine to form another.

CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl

This is a double displacement reaction. Both compounds exchange their cations and anions.

Zn + CuSO₄ = Cu + ZnSO₄

This is a single displacement reaction. A metal displaces other metal from its salt.

2 Na₂O = 4 Na + O₂

This is a decomposition reaction. A compound decomposes into 2 other compounds.

The presented reactions are:

S + O₂ ⇒ SO₂    Synthesis or combination

CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl   Double displacement

Zn + CuSO₄ = Cu + ZnSO₄   Single displacement

2 Na₂O = 4 Na + O₂   Decomposition

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Unit for Acceleration is m/s² or ms raised to -2

Answer:

Decreasing the angle to 10

Explanation:

Edge 2020

Answer:

b

Explanation:

The factor that is most likely to be responsible for the changes observed in the world's rainforest is human activities.

There has been a surge in the human population leading to an increased need for housing, foods, and other infrastructures. All these needs are directly or indirectly provided by the forest. Hence, the more the population of human expands, the more pressure that would be exerted on the rainforest and, indeed, other forests of the world.

The correct option is b.

Answer:

well it would be (A) Gravitational force would increase by a factor of 3.

Explanation:

because the moon is the only thing that gained mass not the Earth

Answer:

The SI is founded on seven SI base units for seven base quantities assumed to ... The SI derived units for these derived quantities are obtained from these ... mass density, kilogram per cubic meter, kg/m3 ... amount-of-substance concentration, mole per cubic meter, mol/m3 ... solid angle, steradian (a), sr (c), -, m2·m-2 = 1 (b).

Kilogram is a derived SI unit of the following.

Thus, A universal standard for expressing the magnitudes or quantities of significant natural events is the International System of Units.

The acronym SI, which derives from the French term Systèm international  stands for the System of Units, also known as the metric system. The meter-kilogram-second (MKS) system, an earlier unit of measurement, serves as the foundation for the SI standard.

The SI standard is promoted and explained by the Bureau international des poids et mesures (BIPM). The organization was founded in 1875 and is known as the International Bureau of Weights and Measures in English. It is governed by the International Committee for Weights and Measures (CIPM).

Thus, Kilogram is a derived SI unit of the following.

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Explanation:

Hey there!

We know that the objects in vacuum falls equally on the surface or bottom. As there is no air resistance in vacuum, the objects has equal stabdard acceleration. (i.e g = 9.8m/s^2)

So, the acceleration due to gravity is 9.8m/s^2.

Hope it helps....

Answer:

a) El punto de colisión de los dos automóviles desde donde parte el conductor del automóvil A es de aproximadamente 293,14 metros.

b) La velocidad del automóvil A, en relación con la velocidad del automóvil B, es de 15 m / s

Explanation:

Los parámetros del movimiento son;

La distancia entre ambos coches = 500 m

La aceleración de ambos coches = 15 m / s²

La dirección de movimiento de ambos coches = uno hacia el otro

La hora de inicio del conductor A = Un segundo antes de la hora de inicio del conductor B

Por lo tanto, de la ecuación de movimiento, tenemos;

s = u · t + 1/2 · a · t²

v² = u² + 2 · a · s

Dónde;

u = La velocidad inicial de los autos = 0 (los autos parten del reposo)

t = El tiempo de movimiento de una aceleración dada

a = La aceleración = 15 m / s²

s = La distancia recorrida en el tiempo t

Por lo tanto, para el controlador A, tenemos;

s₁ = 0 × (t + 1) + 1/2 × 15 × (t + 1) ² = 7.5 × (t + 1) ²

s₁ = 7.5 × (t + 1) ²

Para el conductor B, tenemos;

s₂ = 0 × t + 1/2 × 15 × t² = 7.5 × t²

s₂ = 7,5 × t²

Dado que ambos chocan a lo largo del camino de 500 m, tenemos;

s₁ + s₂ = 500 metros

∴ 7.5 × (t + 1) ² + 7.5 × t² = 500

∵ s₁ + s₂ = 7.5 × (t + 1) ² + 7.5 × t²

Lo que da;

15 · t² + 15 · t + 7.5 = 500

15 · t² + 15 · t - 492,5 = 0

Resolver usando la aplicación en línea da; t = -6,25181 o t = 5,25181

Dado que t es un número natural, tenemos el valor correcto para t = 5.25181 segundos

a) Por tanto, el punto de colisión de los dos coches desde donde parte el conductor del coche A es;

s₁ = 7.5 × (t + 1) ² = 7.5 × (5.25181 + 1) ² ≈ 293.14 metros

El punto de colisión de los dos automóviles desde donde parte el conductor del automóvil A ≈ 293,14 metros

b) La semilla de A en el punto de colisión se da de la siguiente manera

Velocidad, v₁ = u + a × (t + 1) = 0 + 15 × (5.25181 + 1) ≈ 93.78

v₁ ≈ 93,78 m / s

La semilla de B en el punto de colisión también se da de la siguiente manera

Velocidad, v = u + a × (t) = 0 + 15 × 5.25181 ≈ 78.78

v₁ ≈ 78,78 m / s

Por lo tanto, la velocidad del automóvil A, en relación con la velocidad del automóvil B, [tex]v_{relative}[/tex] se da como sigue;

 = v₁ - v₂ = 93,78 m / s - 78,78 m / s = 15 m / s

la velocidad del automóvil A, relativa a la velocidad del automóvil B = 15 m/s.

Answer:

true

Explanation:

Protons and neutrons are found in the nucleus