I'll give brainliest!

During the last 5 million years, how often have the poles reversed
themselves?
5
20
10
15

Answer:

B

Explanation:

the external force was applied

Answer:

Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2). Acceleration is also a vector quantity, so it includes both magnitude and direction.

Explanation:

Answer: i think its b

sorry if im wrong

Explanation:

Answer:

a) El remolque desciende 7.4 cm

b) La carga debe ser de 15715.6 N ó 1603.6 kg

Explanation:

Para los cálculos que involucren muelles, se aplica la Ley de Hooke, la cual relaciona el efecto de una Fuerza y el cambio de longitud que esta ejerce,  en un resorte de elasticidad dada.

Escrito en fórmula:

[tex]F=-k \cdot \Delta L[/tex]

Donde:

F es la fuerza ejercida

k es la constante elástica del muelle

ΔL es la variación de longitud del muelle

El problema indica que al cargar 2100 kg se ejerce una fuerza de 20580 N

Esto se corrobora con la 2da ley de Newton y asumiendo una aceleración de gravedad de 9.8 [tex]\frac{m}{s^{2} }[/tex]

[tex]F_{1} =m \cdot a\\F_{1}=2100kg \cdot 9.8\frac{m}{s^2}\\F_{1}=20580N[/tex]

Esta fuerza comprime o reduce la longitud del muelle en 5.5 cm. Usando estos datos en la Ley de Hooke, podemos obtener la constante elástica k:

[tex]F=-k \cdot \Delta L\\20580N=-k \cdot (-0.055m)\\\\k=\frac{20580N}{0.055m}\\k= 374181\frac{N}{m}[/tex]

Ahora ya tenemos los datos para resolver las preguntas:

Aplicando directamente la formula de la Ley de Hooke:

[tex]F=-k \cdot \Delta L\\\Delta L=\frac{F}{-k} \\\Delta L= \frac{28000N}{-374181\frac{N}{m}} \\\Delta L=-0.074 m = -7.4cm[/tex]

En este caso debemos calcular la fuerza necesaria que haga descender el remolque 4.2cm. Nuevamente utilizando la Ley de Hooke con estos nuevos datos:

[tex]F=-k \cdot \Delta L\\F=-374181\frac{N}{m} \cdot (-0.042m)\\F=15715.6N[/tex]

Si queremos saber la carga en kilogramos:

[tex]F = m \cdot a\\m = \frac{F}{a} \\m = \frac{15715.6N}{9.8\frac{m}{s^2} }\\m= 1603.6 kg[/tex]

Answer:

Because the energy is waning

Explanation: hope this helps

Answer:

Air moves from the areas of higher temperature to areas of lower temperature.

Explanation:

this is because hotter temperatures seek out colder temps.

hope this helped!

When a teacher opens a window on a cold day. the room starts to feel cooler because air moves from the areas of higher temperature to areas of lower temperature.

The transfer of heat between two bodies by currents of moving gas or fluid is known as convective heat transfer. In free convection, air or water rises and is replaced by a cooler parcel of air or water as it moves away from the hot body.

As air moves from the areas of higher temperature to areas of lower temperature, when the teacher opens a window on a cold day, the air in the room moves out side and cold air takes the position inside the room. So, it feels cooler then.

To find more about convection, refer the link:

https://brainly.com/question/16635311

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Answer:

d

Explanation:

Answer:

5.3 m/s

Explanation:

Answer:

10m/s

Explanation:

Though the question does not ask for anything, I'll assume you need to calculate the speed of the lift.

Answer:

The lift travels at 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its state of motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is usually expressed in Joules (J)

If we already know the value of the kinetic energy, we can find the speed by solving for v:

[tex]\displaystyle v=\sqrt{\frac{2K}{m}}[/tex]

The lift has a mass of m=4200 Kg and has a kinetic energy of K=4116 J, thus it's moving at a speed of:

[tex]\displaystyle v=\sqrt{\frac{2*4116}{4200}}[/tex]

[tex]\displaystyle v=\sqrt{1.96}[/tex]

v = 1.4 m/s

The lift travels at 1.4 m/s

Answer:

speed = distance/time

Explanation:

speed = 150/30

speed =5m/s

you were running fast .....5m/s is a good speed

Answer490N:

Explanation:

Answer:

potential

Explanation:At this point the energy is stored in a form called potential energy. This means that the system has the potential to do work or to become active thanks here to the weight's position high above the lowest point of its swing.

Answer:

Invasive species alter and degrade the environment, and have a negative effect on both native species and the people who live and work there. The impacts of invasive species include: Reduced biodiversity. Decreased availability and quality of key natural resources.

Explanation:

Hope this helps!

Answer: 10^5

Explanation:

Answer:

Ceiling fan

Explanation:

Ceiling fan is a perfect and typical example of electrical energy being converted to mechanical energy.

In most systems, energy is usually transformed from one form to another. Energy is not created neither is it destroyed. We know this by virtue of law of conservation of energy.

Answer:

22.5 kg

Explanation:

solve for mass in the kinetic energy equation then round to a whole number

A beaver runs at a speed of 2.0 m/s with 45 J of kinetic energy.

What is the beaver’s mass?

Answer: 22.5 kg

Answer:

D

Explanation:

descriptive, because scientists are writing down the observations but not making comparisons.  

The answer is C. Rectum.

Answer:

You have a severe case.

Explanation:

My anus smells foul, like poop or diarrhea. Why? Like your anus might be tired of making the same old sensational brown. No fear needed! Anus Maker is here! With this app, you can post poop photos for help if you need! No more foul sensational browns! Start your free Anus Maker trial today!

Answer:

For the car to move with constant velocity the additional force required is  [tex]F__{dg} }= -3674 \ N[/tex]

Explanation:

From the question we are told that

  The net force of the car is  [tex]F_{net} = 3674 \ N[/tex]

Generally the total  force acting on the  car is the net force plus the force due to gravity acting in direction of the car (Let denote it as [tex]F__{dg}[/tex])

So the total force acting on the car is mathematically represented as

        [tex]F_{net} + F__{dg}} = F[/tex]

Here this F representing the total force can be mathematically represented as

      [tex]F = ma[/tex]

Now for constant velocity to be attained, the acceleration of the car will be zero  

So  at constant velocity

       [tex]F = m * 0[/tex]

=>    [tex]F = 0 \ N[/tex]

So  

     [tex]F_{net} + F__{dg}} = 0[/tex]

=>   [tex]F__{dg} }= -F_{net}[/tex]

=>   [tex]F__{dg} }= -3674 \ N[/tex]

The potential energy of the rock at the top of a 30 meter tall hill is 4414.5 J.

Potential energy is the energy possessed by an object because of its position (in a gravitational or electric field), or its condition (as a stretched or compressed spring, as a chemical reactant, or by having rest mass).

The formula for potential energy depends on the force acting on the two objects. For the gravitational force, the formula is:

P.E = m × g × h

Where;

According to this question, a rock is at the top of a 30 meter tall hill. If the rock has a mass of 15kg, the potential energy can be calculated thus;

P.E = 15kg × 9.81m/s² × 30m

P.E = 4,414.5J

Therefore, 4,414.5Joules is the potential energy of the rock.

Learn more about potential energy at: https://brainly.com/question/24284560

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If there are no dissipative forces acting on the string, than the principle of conservation of energy holds.

When the string is relaxed, it has zero elastic potential energy

If we were strech the she spring, we would increase it's potential energy. After releasing the spring, when it's relaxed again, all potential energy will have been converted into kinetic energy.

Therefore, the elastic potential energy of the stretched spring should be equal to the amount of kinetic energy when it's relaxed

Answer:

okay

Explanation:

okay

Answer:

Cool

Explanation:

Answer:

force ; connected ; slow ; slipping.

Explanation:

Friction is the force that occurs when two objects are in contact and they oppose relative motion of the two surfaces. The frictional forces always tries to oppose the relative motion between two objects. It makes the things to move slowly or slow down the speed by opposing its relative motion. It avoids slipping of any objects which makes objects stands slipping.

Answer:

The maximum distance Charles will push down the trampoline ≈ 0.342 m

Explanation:

The given parameters are;

The mass of the trampoline artist, m = 75 kg

The speed with which the trampoline artist lands, v = 9.0 m/s

The value of the spring constant of the trampoline, k = 52,000 N/m

Let x represents the maximum distance Charles will push down the trampoline

Therefore, we have;

Kinetic energy = 1/2·m·v²

The kinetic energy with which the trampoline artist lands  = 1/2 × 75 × 9.0² = 3037.5

The kinetic energy with which the trampoline artist lands  =  3037.5 J

The potential energy stored in a spring = 1/2·k·x² = The kinetic energy with which the trampoline artist lands

∴ 1/2 × 52,000 × x² = 3037.5

∴ x = √(3037.5/(1/2 × 52,000)) ≈ 0.342

The maximum distance Charles will push down the trampoline = x ≈ 0.342 m

F=m*a

350N=m*1.4m/s^2

m=350N/1.4m/s^2=250kg

Answer:

Option B. 30 Km/h

Explanation:

To solve this question, we must know the meaning of average speed.

Average speed is simply defined as the total distance travelled divided by the total time taken to cover the distance. Mathematically, it is expressed as:

Average speed = Tota distance /Total time

Thus, with the above formula, we can obtain the average speed of the entire trip as shown below:

Total distance = 60 Km

Total time = 2 h

Average speed = Total distance /Total time

Average speed = 60 /2

Average speed = 30 Km/h

Thus, the average speed of the entire trip is 30 Km/h

Answer:

I think it is B maybe A

Explanation:

Answer:

7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)

Explanation:

7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)