Answer:
A
Explanation:
A circle graph typically represents numbers in percentages, used to visualize a part to whole relationship or a composition
Answer:
In a closed system, the total energy is conserved or remains the same as energy transformations take place.
Explanation:
The law of conservation of energy states that energy cannot be created or destroyed but can be transformed from one form to another.
This law of conservation of energy applies only to a closed system. A closed system is a system which does not exchange energy with its surroundings. All forms of energy conversions occurring within a closed system does not result in an increase or decrease of the total energy of the system, rather, energy remains constant. For example, the universe is a closed system in that all forms of energy conversions occurs within it and energy is not exchanged with an external environment. However, the earth is not a closed system as some of the energy it receives from the sun can be radiated out into space. Since it's an open system, its total energy can change.
Answer:
Periodic.
Explanation:
Electromagnetic waves is a propagating medium used in all communications device to transmit data (messages) from the device of the sender to the device of the receiver.
Generally, the most commonly used electromagnetic wave technology in telecommunications is radio waves.
Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m. Therefore, radio waves are a series of repetitive valleys and peaks that are typically characterized of having the longest wavelength in the electromagnetic spectrum.
Basically, as a result of radio waves having long wavelengths, they are mainly used in long-distance communications such as the carriage and transmission of data.
Generally, a fixed speed is used for the propagation of traveling waves and this speed is usually denoted with the variable "v" or sometimes "c."
Furthermore, if the waveform of a traveling wave is repeated every time at specific intervals T, it is referred to as periodic wave.
Mathematically, the period of a traveling wave is given by the formula;

Where;
T is the time measured in seconds.
i added an image. i hope it helped :)
Newton's third law of motion
Explanation:
Newton's third law of motion states that:
<em>"When an object A exerts a force on an object B (action force), then object B exerts an equal and opposite force (reaction force) on object A"</em>
It is important to note that this law is always valid, even when it seems it is not.
Consider for example the gravitational force that the Earth exerts on your body (= your weight). We can say that this is the action force. It may seems that there is no reaction force in this case. However, this is not true: in fact, your body also exerts an equal and opposite force on the Earth, and this is the reaction force. The reason that explains why we don't notice any effect on Earth due to this force is that the mass of the Earth is much larger than your mass, therefore the acceleration produced on the Earth because of the force you apply is negligible.
It is also important to note that the action-reaction pair of forces always act on two different objects, so they never appear in the same free-body diagram.
Learn more about Newton's third law of motion:
brainly.com/question/11411375
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