Physics Lab #7
Projectile Motion III
Theory
See the theory section from the last lab.
Procedure
In a new window, open the physics applet (physlet) here
to do this lab:
- From the physlet,
tabulate the data x, y and t for times from 0.0 to 5.5 s. Input the data into Excel for
efficiency. Choose times steps to make
sure you get around 20 to 30 data points.
The position of the ball is found by clicking with the mouse in the
center of the ball.
- Estimate the launch angle of
the ball by looking at the (nearly) straight line path it takes for the
first couple of squares and using trig.
- Draw the graph of x vs. t
using Excel. What is the shape of
the graph? What does that tell
you? What does the slope represent
(look at the equation for the x motion)?
From the slope and the angle found in step 1 calculate the initial
speed of the ball.
- Consider the equation for the
y motion. What do you expect the
graph of y vs. t to look like?
Graph it to check out your expectation. Use the values of angle, initial value
of speed as calculated and the know value of g to add another column of
data representing theoretical values for y. Compare it number by number
and graphically to see if it agrees with the experimental data.
- Use the formulas for H, R and
T to find the expected values and compare them to those read off the physlet.