a) Newton's law of motion states that the acceleration acting on a falling body

(assuming no other forces) is �
x" = -g, where x(t) is the height of the object
above the ground, t is time, and g is the gravitational constant. Find a general
expression to describe the height of the object above the ground with respect
to time, t; i.e. find x(t).
(b) Suppose the object is dropped from a height of 100 units (so x'(0) = 0 and
x(0) = 100), how long will it take to hit the ground?

1 answer

x"=-9.8
x'=INT (-9.8)=-9.8t+x'(0)
x= INT (-9.8t+x'(0))
= x'(0)*t-1/2 9.8t^2 + x(0)

b) given x(0)=100, x'(0)=0
x=-4.9t^2 if x=-100
then t= sqrt(100/4.9) when it hits the ground.