a 250kg boulder drops from a 35 meeter cliff. The force of air acting on it is 12N. How fast is the rock moving before it hits the ground?

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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it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.

with the invention of the automobile, the woman of the house could drive to the store and get groceries. women were also free to socialize more. during world war ii women were allowed to work in factories to the war effort and could drive to work or ride mass transit buses to their jobs.

this is a good question! i'll do some research and come back when i have the answer!