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.
Answer: 1,500m/s
Explanation:
Relationship existing between velocity of a wave (v), wavelength(¶) and frequency(f) is
v = f¶... (1)
Since Frequency (f) is the reciprocal of the period (T);
Frequency = 1/Period i.e F = 1/T... (2)
Substituting equation 2 into 1 we have;
v = 1/T × ¶
v = ¶/T
Given wavelength ¶ = 9m
Period T = 0.006s
v = 9/0.006
v = 1,500m/s
The velocity of the wave will be 1,500m/s
Answer:
um how about no.. this is not the site for what you're looking for...
Explanation:
That is the Sigma Symbol. It’s the addition of a sequence of numbers; the result is the sum of the total. if numbers are added sequentially from left to right, any intermediate result is a partial sum, prefix sum, or running total of the summation
A (b) would be 42 (c) from x to Y mark me as brainlist thanks