data analysis

Experiment 3: Conservation of Energy- Data Analysis

In this experiment you will apply your knowledge of Conservation of Energy to a given data set. Table 5 contains data for the position of a ball with mass 0.5 kg that has been dropped from 5 meters from rest at given time points. In order to test the conservation of energy, the potential energy and kinetic energy of the ball need to be calculated.

Materials Table 5

Procedure

1. To calculate the kinetic energy, the velocity of the ball needs to be known. From the given table, only position is provided. To find velocity, a method called the "leap-frog” method can be used to approximate the velocity using the position and time points just before and after:

v=	Δx
	Δt

The first velocity point has been done for you as an example:

v =	Δx	=	x3 - x1	=	0.10 m- 0.00 m	=	- 0.40 m/s
	Δt		t3 - t1		0.496 s - 5.00 s

2. Use this method to calculate the other velocities. Record the velocities in Table 5.

Table 5: Dropped Ball Data
Time (s)	Ball Position (m)	Ball Velocity (m/s)	Potential Energy (J)	Kinetic Energy (J)	Total Energy (J)
0.00	5.00
0.05	4.99
0.10	4.96
0.15	4.89
0.20	4.78
0.25	4.69
0.30	4.54
0.35	4.40
0.40	4.22
0.45	4.00
0.50	3.80
0.55	3.50
0.60	3.26
0.65	2.93
0.70	2.60
0.75	2.23
0.80	1.88
0.85	1.46
0.90	1.05
0.95	0.58
1.00	0.11

Post-Lab Questions

1. Graph the potential energy, kinetic energy, and total energy of the ball.

2. Describe the shape of each graph.

3. What are the limitations of using the leap-frog method?