The sentence can be completed as follows:
The wavelength of an electromagnetic waves is the spatial distance between two successive troughs.
Note that the wavelength of a wave can also measured as the spatial distance between two successive crests of the wave. Also note that the second part of the sentence ("also known as the period") is not true, because period is another thing (in fact, the period is the time interval between two successive troughs).
Answer:
Explanation:
Given
Two projectile is fired vertically upward
One has 4 times the mass of other
When Projectile is fired their trajectory is independent of mass of object. Also if they launched with same speed then both achieved same maximum height in same time and will hit the ground at the same moment.
Electromagnets are used for various purposes but I fathom in this instance, the questioner is asking about how electromagnetics can be used to attraction or repulsion.
Example, electromagnets are used for attraction in cranes which attach them to containers in order to lift them.
Meanwhile, Maglev trains use electromagnets repulsive properties.
Answer: They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
Explanation: On Edgenuity!!
The work is 90 as 5 times 18