algebra 1
posted by lily .
The formula for the height of a falling object is shown below, where h is the height of the object in meters, t is the time in seconds, and k is the height, in meters, from which the object began its fall.
h = –4.9t² + k
If a rock is dropped from a building that is 150 meters tall, what is the height of the rock 4 seconds after it was dropped?

h = 4.9(4)^2 + 150 = ?

is it 145.1

not it is 71.6 right

Right!

if an object is dropped from a great height, its speed "v" varies directly with the time "t" it has been falling . a rock dropped over the edge of a canyon is traveling 39.2 m/s after 4 sec.
1. Express v as a function of t.
2. what is the speed of the rock after 9 seconds 
Falling Object An object is dropped from a
height of 576 feet. How long does it take for
the object to reach the ground? Assume there
is no air resistance