A 20.0 Ohm and 60.0 Ohm resistor are connected in series to a 9.00 V
battery. What is their equivalent
resistance?
(Unit = Ohms)

for resistors in series, add the resistances to get their equivalence. The answer is

80.0 Ohms

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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