The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points.
Explanation:
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Answer:
Charge
Explanation:
Unit of ampere is defined as the coulomb of charge per unit time which is in seconds.

Here, i is in ampere, qis the charge which is in coulomb, and the t is in sec which is time.
Therefore,

Charge=ampere-second.
Therefore, the unit ampere-second will represent the charge.
Astronomers give stars names so that they're able to identify and keep track of them more easily.
Answer:
4L
Explanation:
mass of pendulum = M, length of pendulum, L1 = L,
acceleration due to gravity = g, Amplitude = A
Use the formula for the time period for simple pendulum
..... (11)
Let the new length be L2 for which the time period is 2T.
..... (2)
Divide equation (2) by equation (1)

So, L2 = 4 L
Thus, the length of the pendulum is 4 L.