In the phenomenon known as the photoelectric effect, electric current will flow when light shines on certain substances.

Yes, the given statement is correct.

Explanation:

In the phenomenon photoelectric effect, when photon(energy packet of light) falls on a conductor or semiconductor emits electron and when that electron passes through a closed circuit electric current flow though it. This photoelectric effect have vast application now a days such as:- solar cell, photo cell,solar pump.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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