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
To find the height of the rock 4 seconds after it was dropped, we need to substitute the values given into the formula and solve for h.
Given:
k = 150 meters
t = 4 seconds
Let's substitute these values into the formula and calculate the height:
h = -4.9t^2 + k
First, let's calculate 4.9t^2:
4.9 * 4^2 = 4.9 * 16 = 78.4
Now, substitute this value into the formula:
h = -78.4 + 150
Simplifying:
h = 150 - 78.4
h = 71.6
Therefore, the height of the rock 4 seconds after it was dropped is 71.6 meters.