All object accelerate towards the earth at what speed?

9.8 meters per second.

Objects fall to the ground at the same rate because the acceleration due to gravity is the same for all objects. All objects accelerate towards earth at a rate of 9.8 meters per second. this means that for every second that an object falls, the objects downward velocity increases by 9.8 m/s.

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.

read more on -

scientific laws are the result of testing theories and proving them to be facts.