The amount of space an objective takes up measures by volume.
<u>Explanation:</u>
Volume is a proportion of the measure of space, unfilled column that a substance or an item takes up. The essential SI unit to volume denotes in the (cubic meter), yet volumes might be estimated in cubic centimetres, and fluids might be estimated in liters (L) or milli-liters (mL). How the volume of matter is estimated relies upon its state. The fluid's volume is estimated with an estimating holder, for example, an estimating cup or graduated chamber.
The gas volume relies upon the volume of its holder: gases able to occupy anything that space is accessible to them. The occupied space of a routinely molded strong can be determined from its measurements. For instance, the rectangle’s volume strong is the result of its width, length, and stature. The volume of a sporadically molded strong can be estimated by the uprooting technique.
Answer:
Option D.
Value cannot be calculated without knowing the speed of the train
Explanation:
The speed of the beam can only be calculated accurately when the speed of the train is put into consideration. Based of the theory of relativity, the observer is on the ground, and the train is moving with the beam of light inside it. This causes a variation in the reference frames when making judgements of the speed of the beam. The speed of the beam will be more accurate if the observer is moving at the same sped of the train, or the train is stationary.
To get the correct answer, we have to subtract the speed of the train from the speed calculated.
-- The unit of frequency is "per second" (Hz), which is [reciprocal time].
-- The unit of period is "second", which is [time].
Do you see where this is going ?
'Frequency' and 'period' are reciprocals of each other.
For any wave ...
Period = (1) / (frequency) .
Frequency = (1) / (period) .
