Today's lab will demonstrate the relationship between kinetic and ...
Today’s lab will demonstrate the relationship between kinetic and potential energy. Kinetic energy is energy of motion. The kinetic energy of the marble is converted from the potential (stored) energy it has at the top of the hill. As the marble travels it trades potential and kinetic energy back and forth. The law of conservation of energy states that energy can be converted from one form to another but not created or destroyed. You will be placing the photogate at seven different positions and recording the times for two marbles of different mass. You will be calculating, then graphing, the speeds and comparing them each other and to the height of the marble on the coaster track. Write out the six steps of the scientific method. Write out your four problem statements. Research: kinetic energy, potential energy, law of conservation of energy, speed, rotational torque, photogate, infrared beam, stored energy, entropy, inertia, kinetic friction, rolling friction. Write out your four hypotheses.
Position
Time at photogate (sec)
number steel marble
1 2 3 4 5 6 7
plastic marble
Distance
Speed of marble (cm/sec)
traveled by
s=d/t
marble (cm)
steel marble
plastic marble
Use your measurements to make a graph showing the relationship between height and speed. The graph provided already shows the height of the roller coaster plotted against the position along the track. Using the data from your data table, plot the speed vs. position on the same graph.
• • •
On the graph, plot the speed at each of the seven positions. Connect the dots with a best-fit curve. On the graph, label the two spots where kinetic energy (Ek) is the greatest. On the graph, label the two spots where potential energy (Ep) is the greatest. Use the graph and data to answer the questions. Write your four (4) conclusions.
Questions 1) What is the relationship between marble speed and height above the table?
2) Where is the speed of the marble the greatest? …the least?
3) Does the uphill or downhill direction affect the speed at the same height (compare positions 2 and 4)?
4) How are potential and kinetic energy related in this experiment?
5) How does the marble mass affect the speed?
Position
Time at photogate (sec)
number steel marble
1 2 3 4 5 6 7
plastic marble
Distance
Speed of marble (cm/sec)
traveled by
s=d/t
marble (cm)
steel marble
plastic marble
Use your measurements to make a graph showing the relationship between height and speed. The graph provided already shows the height of the roller coaster plotted against the position along the track. Using the data from your data table, plot the speed vs. position on the same graph.
• • •
On the graph, plot the speed at each of the seven positions. Connect the dots with a best-fit curve. On the graph, label the two spots where kinetic energy (Ek) is the greatest. On the graph, label the two spots where potential energy (Ep) is the greatest. Use the graph and data to answer the questions. Write your four (4) conclusions.
Questions 1) What is the relationship between marble speed and height above the table?
2) Where is the speed of the marble the greatest? …the least?
3) Does the uphill or downhill direction affect the speed at the same height (compare positions 2 and 4)?
4) How are potential and kinetic energy related in this experiment?
5) How does the marble mass affect the speed?
