FREE+FALL

Back Ground: One common law on earth is the law of gravity, basically things fall. In this unit you will be examining different forces and how they relate to the manner in which falling occurs under __**constant acceleration**__.

FORMULAS TO KNOW:

Vertical velocity = a t

Vertical distance = ½ a t2

ESSENTIAL QUESTIONS: What is the relationship between the changes that occur in speed, acceleration, and distance of a falling object over time.

USE THE FOLLOWING VOCABULARY WORDS TO ANSWER THE ESSENTIAL QUESTION IN YOUR CORNEL NOTES:

> ==Gravitational Acceleration (g) == > Upward Velocity > Downward Velocity
 * ==Free Fall ==
 * ==Gravitational Force ==

Click the link to understand Free Fall in a more detailed manner:

TRY A PRACTICE PROBLEM ANSWERS ARE AT THE BOTTOM OF THE PAG E =**A baseball is popped straight up into the air and has a hang-time of 6.25 s. Determine the height to which the ball rises before it reaches its peak. (Hint: the time to rise to the peak is one-half the total hang-time.)**=

d = ?? ||
 * || a = -9.8 m/s2 || vf = 0 m/s || t = 3.13 s || || Find:


 * 1) (NOTE: the time required to move to the peak of the trajectory is one-half the total hang time.)

First use: vf = vi + a*t

0 m/s = vi + (-9.8 m/s2 )*(3.13 s)

0 m/s = vi - 30.6 m/s

vi = 30.6 m/s

Now use: vf2 = vi2 + 2*a*d

(0 m/s)2 = (30.6 m/s)2 + 2*(-9.8 m/s2 )*(d)

0 m2/s2 = (938 m/s) + (-19.6 m/s2 )*d

-938 m/s = (-19.6 m/s2 )*d

(-938 m/s)/(-19.6 m/s2 ) = d

d = 47.9 m