# Energy Physics Lab

Energy and the Roller Coaster (B-1)

1. Making a prediction
a. Watch the marble roll along the track. At which place do you think the marble moves fastest? Why?
I think that the marble moves fastest at position 7 because the marble has been rolling downwards the longest at that point.

2. Measuring the speed of the marble

Table 1: Speed of the Marble on the Roller Coaster
Position number Time from
photogate A
(sec) Distance traveled by marble
(cm) Speed
of marble
(cm/sec)
1 0.0108 45 175.9
2 0.0135 25 140.7
3 0.0303 80 62.7
4 0.0158 65 120.3
5 0.0112 50 169.6
6 0.0150 100 126.7
7 0.0098 125 193.9

a. Did your measurements agree with your hypothesis, or did they point to a different hypothesis?
Yes, my measurements agreed with my hypothesis.

b. What did you notice about the motion of the marble from the measurements?
The when the marble goes up the hill it slows down and when the marble goes downhill it speeds up.

3 Energy conservation
Table 2:Speed, Height, and Position

Position (cm) Height (cm) Time from photogate A (sec) Distance traveled by marble (cm) Speed of marble (cm/sec)
25 23 0.0135 1.9 140.7
30 19 0.0113 1.9 168.1
35 16 0.0113 1.9 168.1
40 14 0.0106 1.9 179.2
45 15 0.0107 1.9 177.6
50 16 0.0109 1.9 174.3
55 19 0.0120 1.9 158.3
60 22 0.0121 1.9 157.0
65 26 0.0156 1.9 121.8
70 28 0.0194 1.9 97.9
75 30 0.0251 1.9 75.7
80 32 0.0287 1.9 66.2

4. Graphing speed and height

Height and Speed vs. Position

a. What can you tell from your graph? Describe the relationship between the speed of the marble and the height.

b. Where is the speed of the marble the greatest?
The speed of the marble is the greatest when it’s at the position 40cm, and it’s height is 14cm

c. Does the uphill or downhill direction affect the speed of the marble, or is height the only contributing variable?
Rolling downhill will make the marble’s speed increase and rolling uphill will decrease the marble’s speed.

d....