# Momentum

Title: Energy in Roller Coasters
Problem: How much energy is “lost” on a roller coaster-like track?
Hypothesis: Due to the principle of conservation of energy, all energy should be conserved in some form. Most of the initial energy should be conserved, although error may occur.
Procedure: 1. Place a metal marble on top of the roller coaster-like model.
2. Measure the height to the center of the marble.
3. Place two infrared timers along the track.
4. Measure the height of each location and record the distance down the track.
5. Roll the marble down the track and record data.
6. Repeat trial three times.
7. Repeat 3—6 four times.
Materials:
• Roller Coaster Track
• Marble
• Timers
• Meter Stick
Data: Distance, Height, and Time
Trial Distance (cm) Height (cm)
(±2mm) Time (s)
(±.0005)
1 20 27 .0159
80 31.5 .0303
2 10 32 .0265
100 25 .0151
3 40 14.5 .0112
120 12 .0103

4 50 15.5 .0115
60 23 .0131
5 5 35 .0489
125 10 .0098
Initial 0 36.5 0.000
Vi=0, h=.365, m=m KE1¬¬ + PE1= KE2 + PE2 + Wf E¬total=1/2mv2 + mgh
Etotal=1/2m(0)2 + m(10)(36.5) Initial Etotal¬=365m v = d/t where d = .019

Kinetic, Potential, Total Energy, and Work of Friction
Trial Kinetic E Potential E Total E
1 79.4m 270m 349.4m
349m 315m 664m
2 7.22m 320m 327.22m
2190m 250m 2440m
3 637m 145m 782m
6790m 120m 6190m

4 946m 155m 1101m
1050m 230m 1280m
5 .500m 350m 350.5m
8140m 100m 8240m
Percent difference.
(PEi-TE)/PEi *100%