Two general kinematic
equations derived earlier in the semester were:
y = yo
+ vot + ½ at2 V =
vo + at
where y =
distance
yo
= initial distance
vo
= initial velocity
t = time
in the air
a =
acceleration due to gravity (9.8 m/s2 on Earth)
Regularly in a free fall
problem there is no initial velocity and distance, therefore the
equations simplify to:
y = ½ at2
v = at
where y = Height
from where the object is dropped
t = time
in the air
v =
velocity of the object before it hits the ground
a =
acceleration due to gravity (9.8 m/s2 on Earth)
Knowing where the object is
dropped from, the first equation can be manipulated to determine total
time.
t =
Visit the following link to
view a graphic and calculated example of a free falling situation. Set
initial conditions and gather data to perform the actual calculations.
http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html#ffall
Assessment.
1)
Email complete solutions to the following problems to the
instructor.
a)
What is the time it takes for a brick to drop from a height of
20 m above the ground? What is the final velocity before it hits the
ground?
b)
The time it took an object to hit a ground was 2.5 sec. From
what height was the object dropped?
2)
Using the Internet link above, design a free falling problem. Trade
and Email your problem to a classmate to solve. Submit the designed
and solved problems to the instructor through email.
