Graphical Analysis of a Bounced
Ball (see sample graph below)
1. With the
computer ready for data collection, drop a large bounce ball from
the specified height until the computer graphically records acceptable
d-t and V-t graphs showing two complete bounces.
2.
With the AGraph@
function from the menu, Amark@
the region of the graphs using the arrow keys, then Azoom@
to that region. Print
both graphs together for analysis.
(record mass of ball for further calculations)
Analysis of Graphs
A. Distance vs
Time Graph
1a.
Label the portion of the graph where the ball is falling,
rising, then falling again; mark the point where the ball reversed
direction, then draw a vertical line down to the V-t graph.
b. What is the velocity of the ball at this point?
Explain.
2a. Label the point where the ball
is at the top of its path after bouncing.
b. What is its velocity at this point? What
is the acceleration?
c. Determine the difference in height between height released
and height attained on the bounce, then determine the COR for
your ball.
1.
Label the lines showing the acceleration of gravity, then
the line showing the acceleration during the bounce.
2. Label the exact point where the
ball first hits the floor, and the exact point where it no longer
has contact with the floor. Compare
the velocities at these two points. Suggest
a relationship between velocity and COR.
3. Label the point where the ball
is under maximum compression, then estimate the time the ball
was in contact with floor. From the
total change in velocity (”v) during the bounce, determine
the impulse J on the floor, then the average force F during the
bounce (J = Ft = m”v).
4. What was the total change in momentum
of the ball during the bounce?
5. Draw right triangles on the portion
of the graph when the ball was in the air on the way down, then
on the portion of the graph on the way back up to the top.
What do these areas represent?
6. Even though the ball stops at the
top of the bounce, the slope on the line continues upward.
Explain.