ASSIGNMENT
Click Examine, , and move the mouse across the position or velocity graphs of the motion of the ball to answer these questions.
- Identify the portion of each graph where the ball had just left your hands and was in free fall. Determine the height and velocity of the ball at this time. Enter your values in your data table.
- Identify the point on each graph where the ball was at the top of its path. Determine the time, height, and velocity of the ball at this point. Enter your values in your data table.
2. 3.
4. 5. 6. 7. 8.
c. Find a time where the ball was moving downward, just before it was caught. Measure and record the height and velocity of the ball at that time.
- Choose two more points approximately halfway in time between the three recorded so far.
- For each of the five points in your data table, calculate the Potential Energy (PE), Kinetic Energy (KE), and Total Energy (TE). Use the position of the Motion Detector as the zero of your gravitational potential energy.
How well does this part of the experiment show conservation of energy? Explain. Calculate the ball’s kinetic and potential energy.
- Logger Pro can graph the ball’s kinetic energy according to KE = 1 mv2 if you supply the 2 ball’s mass. To do this, adjust the mass parameter.
- Logger Pro can also calculate the ball’s potential energy according to PE = mgh. Here, m is the mass of the ball, g is the free-fall acceleration, and h is the vertical height of the ball measured from the position of the Motion Detector. The same mass parameter will be used to find PE.
- Go to the next page of Logger Pro by clicking Next Page, .
Inspect your kinetic energy vs. time graph for the toss of the ball. Explain its shape and print
or sketch the graph.
Inspect your potential energy vs. time graph for the free-fall flight of the ball. Explain its shape and print or sketch the graph.
Compare your energy graph predictions (from the Preliminary Questions) to the real data for the ball toss.
Logger Pro will also calculate Total Energy (TE), the sum of KE and PE, for plotting. Record the graph by printing or sketching.
What do you conclude from this graph about the total energy of the ball as it moved up and down in free fall? Does the total energy remain constant? Should the total energy remain constant? Why? If it does not, what sources of extra energy are there or where could the missing energy have gone?
