Which model shows how a comet's tail changes during its orbit?

Explanation:

We know that the overall mechanical energy of a device stabilizes in the absence of any external force. We know that that the total of potential and kinetic of the freely velocity vector remains same. ,So mechanical energy of a body, underneath gravitation, remains constant.

Answer:

Em = 30 J

Explanation:

The principle of conservation of mass and energy is one of the most important in physics, it establishes that energy cannot be created just by transforming it.

Therefore, the mechanical energy at a point is the same throughout the movement, only in some parts it will be kinetic, in others potential and in the intermediate points a mixture of the two, but the total value is always the same.

           Em = K + U

            Em = 17.5 + 12.5

            Em = 30.0 J

At the point just before touching the ground the mechanical energy is the same Em = 30 J

Answer:

The charge of a neutron is 0  

The charge of an electron is -1

Explanation:

Answer:

The charge of Neutrons is: 0

The charge of Electrons is: -1

Explanation:

Neutrons are uncharged and Electrons are negatively charged. The negative charge of one electron balances the positive charge of one proton. Both protons and neutrons have a mass of 1, while electrons have almost no mass.

Answer: Static Friction

Explanation: As you tilt the book you know that it will stay fixed to start with, but eventually, once the angle is large enough, the book will start to slide. It is the static friction force that holds the book in place at small angles of tilt.

The book remains at rest if A book is resting on a table. The table is raised on one end to an angle of 15° to the floor due to static friction, so option C is correct.

An item is kept at rest by the force of static friction. The phrase "static friction" can be defined as "the friction people perceive when they attempt to move a stationary object on a surface, but without actually causing any relative motion between the body and the surface it is on."

You can predict that the book will initially remain fixed when you tilt it, but once the angle is sufficiently large, it will finally begin to slide. The book is held in place at slight tilt angles by static friction force.

The formula for the coefficient of static friction is μ = tan θ, here θ is the angle of inclination if the angle is bigger the friction force is more but at 90° when the book is vertical then the friction force will not work on the book

Therefore, the book remains at rest if A book is resting on a table. The table is raised on one end to an angle of 15° to the floor due to static friction.

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Answer:

As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. ... Thus, entropy measurement is a way of distinguishing the past from the future.

Explanation:

Period, being a time, is measured in units of time such as seconds, hours, days or years. The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle

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Answer:

False

Explanation:

The formula of force that exists between two charges is expressed as;

F = kq1q2/r²

If two charges separated by one meter exert a 9 N force on each other, the;

9 = kq1q2/1²

9 = kq1q2 ..... 1

If the charges are pushed to a 3 meter separation, then;

F =  kq1q2/3²

F =  kq1q2/9 .... 2

Divide both equations;

9/F = (kq1q2)/ kq1q2/9

9/F =  kq1q2 * 9/ kq1q2

9/F = 9

F = 9/9

F = 1N

Hence if the charges are pushed to a 3 meter separation, then the force on EACH charge will be 1N. Hence the answer is False

Answer:

The thrust that you feel at the time of firing is one of the real-life example of the conseriation nomentum

Answer: the thing that brings you life- h2o- idrk the question but if this helps your welcome ^-^have a good day

Explanation:

Answer:

Kinetic energy and velocity are at zero when the magnets are held apart, and both increase rapidly when they are released and move together. Energy stored in the magnetic field decreases.

Explanation:

easy

The increase in the kinetic energy occurs when both magnets are released.

The kinetic energy and velocity are at zero when the magnets are held apart from one another at a certain distance  but the kinetic energy increases when they are released and move together so we can conclude that the increase in the kinetic energy occurs when both magnets are released.

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Answer:

infrared waves

radio waves

ultraviolet waves

Explanation:

Radio waves are used for communication such as television and radio.

Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark.

Ultraviolet radiation can kill bacteria that are present in water - this sterilises the water and makes it safe to drink.

Answer:

infrared waves

radio waves

ultraviolet waves

Explanation:

Radio waves are used for communication such as television and radio.

Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark.

Ultraviolet radiation can kill bacteria that are present in water - this sterilises the water and makes it safe to drink.

Explanation:

Refractive Index is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density. The refractive index variable is most commonly symbolized by the letter ‘n’ or n’ in a descriptive text and mathematical equations.

Answer:

Answer:

80m/s

Explanation:

to find it you have to work it out by using the formula distance divided by speed to find time.

The time taken by the skateboarder to reach the bottom 120m away is 80 sec.

Acceleration may be defined as the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities as it has both magnitude and direction.

When an object moves in a circular path at a constant speed, it is still accelerating, because the direction of its velocity is changing. If an object is speeding up and moving in a positive direction, it has a positive acceleration.

According to the question,

Speed of the skateboarder = 1.5 m/s

The total distance needs to be traveled = 120m

Total time taken =?

The Formula for calculating time is as follows:

Therefore, the time taken by the skateboarder to reach the bottom 120m away is 80 sec.

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Answer:

there are just a bit over 1.6 km in a mile so 7.5*1.6=12. something so there is just a little bit more distance in 7.5 miles

Explanation:

Answer:

Explanation:

I hope it helps ❤❤

Answer:

The answer is weight.

Mass is constant, your mass, height and width won’t change. So that leaves weight.

Answer:

Final velocity, V = 35.5m/s

Explanation:

Given the following data;

Initial velocity = 28m/s

Acceleration = 2.5m/s²

Time = 3 seconds

To find the final velocity, we would use the first equation of motion

V = U + at

Where;

V is the final velocity measured in m/s.

U is the initial velocity measured in m/s.

a is the acceleration measured in m/s².

t is the time measured in seconds.

Substituting into the equation, we have;

V = 28 + 2.5*3

V = 28 + 7.5

Final velocity, V = 35.5m/s

Answer:

Im pretty sure that it applys

Answer: 2kg

Explanation:

This problem is a textbook conservation of momentum problem. The intial momentum is equal to the final momentum. For the initial state of each block, only the first one was moving. Then they both combine to move together.

Pi = Pf

with p = mv

(6kg)*(4m/s) = (6kg+xkg)(3m/s)

Let x equal the unknown mass of block 2

24 = 18 + 3x

6 = 3x

x = 2kg

Answer:

a then c then b

Explanation:

C.) Year

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Answer:

I believe it's C. Year.

Explanation:

Hope this helps! ^^

Answer:

OD

Explanation:

2 bodies should have different temperatures for energy to be transferred