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:
F - M a force exerted by scales on student
M a = M (9.8 + 4.9) m/s^2 upwards chosen as positive
a = 1.5 g net acceleration of student due to force of scales
W =M g weight of student (actual weight)
Wapp = M 1.5 * g apparent weight (on scales) of student
Answer:
D.The potential energy per unit charge
Explanation:
Electric potential of a charged particle:
It is scalar quantity because it has magnitude but it does not have direction.
It is the amount of work done required to move a unit positive charge from reference point to specific point in the electric field without producing any acceleration.
Mathematical representation:

Where W= Work done
= Unit positive charge
Other formula to calculate electric field:

Where K=
It can be defined as potential energy per unit charge.
Hence, option D is true.
The answer is b, gravity and friction are forces.