### Following the Bouncing Golf Ball

#### Set Up

Obtain a meter stick and golf ball.

#### Experimental Procedure

1. Hold the golf ball center 20 centimeters above the table in front of a vertical meter stick.
2. Drop the golf ball.
3. Measure the maximum height of the first bounce.
4. Record the drop height and bounce in centimeters in the table below.
5. Repeat the procedure for 40 cm and 60 cm.
6. Drop the golf ball on the floor from 80 cm, repeating the rest of the above procedure.
7. Continue dropping the golf ball on the floor for 100 cm, 120 cm, 140 cm, and 160 cm.
8. Find the mass of the golf ball in grams: __________________

#### Table

Drop Height/cm Bounce Height/cm *** Drop Height/cm Bounce Height/cm
20 ____________ *** 100 ____________
40 ____________ *** 120 ____________
60 ____________ *** 140 ____________
80 ____________ *** 160 ____________

#### Graphing the Data

1. Graph the drop height in cm on the x-axis and the bounce height in cm on the y-axis.

#### Calculations

1. Fit a best line to the points.
2. Determine the slope.
1. Pick two points, one near each end of the best fit line.
2. Determine the coordinates of the two points, (x1 , y1) and (x2, y2)
3. Use the formula for determining the slope from two points to obtain the slope:
m = (y2- y1) / (x2- x1)
##### slope m = __________________
1. Determine the y-intercept.
1. Use the formula for determining the slope from two points to obtain the slope:
(y - y1) = m(x - x1)
##### y-intercept = _____________
1. Determine the potential energy at the start of the 160 cm drop.
1. The potential energy of the golf ball can be calculated from PE = mgh where m is the mass of the golf ball in grams, g is the acceleration of gravity (980 cm/s2), and h is the height of the golf ball above the ground in centimeters.  The mass of the golf ball was determined above.  Calculate the potential energy of the golf ball when it is 160 cm above the ground:
PE = mass*(980 cm/s2)(160 cm)
##### PE160 = _____________
1. Determine the potential energy at the top of the first bounce after the 160 cm drop.
1. Calculate the potential energy of the golf ball at the top of its first bounce after a drop of 160 centimeters using the data collected in the laboratory above.

#### Questions

1. What will the bounce height in centimeters be for a drop height of 200 cm?

2. What will the bounce height in centimeters be for a drop height of 4 meters?

3. What will the bounce height in centimeters be for a drop height of 0 cm?

4. Did the golf gain or lose energy between the drop from 160 cm and the top of the first bounce?

5. Energy being conserved, into or from what form was the energy difference converted between the drop from 160 cm and the top of the first bounce?  In other words, what happened to the energy difference?  If the ball gained energy, where did it come from?  If the ball lost energy, into what other forms of energy was the energy converted?