# Down the Hill Lab Report

Only available on StudyMode
• Published : May 28, 2013

Text Preview
Down the Hill Lab Report
Kinetic & Potential Energy

Name: Corinne Chen
Block: 1 – 3
Date: May 22nd, 2013

Purpose:
To investigate and compare the potential energy, kinetic energy and speed of a cart on a hill 1 kg

h
1 m

Materials:
1.
2. Cart & 1 kg mass
3. Board
4. Timer
5. Metre ruler
6. Tape

Data Table:
With 1 kg mass:
Trial #| Distance(m)| Time(s)|
1| 1m| 0.41s|
2| 1m| 0.45s|
3| 1m| 0.44s|

Without 1 kg mass:
Trial #| Distance(m)| Time(s)|
1| 1m| 0.42s|
2| 1m| 0.48s|
3| 1m| 0.45s|

Calculations:

With 1 kg mass:
Average time = 0.4333s
Average velocity = Distance ÷ Average time = 1m ÷ 0.4333s ≈ 2.308m/s Total mass = (7.5N ÷ 9.8N/kg) + 1kg ≈ 1.765kg
Height = 0.33m
Kinetic energy = ½ mv2 = ½ × 1.765kg × (2.308m/s)2 ≈ 4.70J Potential energy = mgh = 1.765kg × 9.8N/kg × 0.33m = 5.71J Without 1 kg mass:
Average time = 0.45s
Average velocity = Distance ÷ Average time = 1m ÷ 0.45s ≈ 2.236m/s Mass = 7.5N ÷ 9.8N/kg ≈ 0.765kg
Height = 0.33m
Kinetic energy = ½ mv2 = ½ × 0.765kg × (2.236/s)2 ≈ 1.91J Potential energy = mgh = 0.765kg × 9.8N/kg × 0.33m = 2.47J

Analysis Questions:

How did the potential and kinetic energy compare (top and bottom of the hill)? Explain using law of conservation of energy. (use values of KE and PE for cart with mass attached) According to the law of conservation of energy, in an isolated system, the initial potential energy and the kinetic energy should be the same. However, when we were doing the experiment, we could not guarantee for ideal situation with no extra resistance, so the data above, which shows that there is difference between the two energies...