Leader: _____________________________ Recorder: ___________________________
Skeptic: _____________________________ Encourager:
_________________________
Laptop
Mini DV camera with cable and power supply
Golf Ball
High Contrast Meter Stick
Black cloth for background (optional)
Tripod (optional)
Projectile
motion occurs when a free falling object has a non-zero initial component of
horizontal velocity. In this lab we will
examine the motion in the x and y directions for projectile motion
Part 1 Launch
and Landing at Same Heights
1. Set-up
In
this lab you will toss a golf ball at approximately a 45° angle above
horizontal and record the motion with a video camera. Position the camera so that you can see the
entire path that the ball will travel.
To obtain accurate data, the camera should be facing forward (not at an
angle) and should be aligned vertically.
Place
the meter stick so that it is visible in the camera and that it lies in the
plane of motion of the projectile.
2.
Data Acquisition
Toss the ball as described above and
observe its path, also known as the trajectory,
with the camera. Adjust the camera and
the speed and angle of launch of the projectile so that you can see the entire
trajectory of the projectile in the camera.
Use LoggerPro to record the trajectory with the camera.
Data Analysis
Use
the slider to position the clip so that you can just see the projectile in the
air after being launched. Click on the
ball until just before it hits the table.
Try to click as accurately as possible to obtain good results.
1.
View the graph for the x position.
Q1)
Describe the shape of the graph of the x position.
Q2)
What does the shape tell you about the motion in the x-direction?
Q3)
Use the linear regression button to add a best fit line to the graph. Record the equation given by the fit.
Q4)
What does the slope you recorded in Q3) tell you?
Print and attach the graph.
2.
View the graph for the x-velocity.
Q5)
Describe the shape of the graph?
Q6)
What does the shape of the graph tell you about the motion in the
x-direction?
Q7)
Does your answer to Q6) agree with your answer to Q2)?
Print and attach the graph.
3.
View the graph for the y position
Q8)
Describe the shape of the graph of the y position.
Q9)
What does the shape tell you about the motion in the y-direction?
Q10)
Use the curve fit button to add a best fit quadratic to the
graph. Record the equation given by the
fit.
Print and attach the graph.
4.
View the graph for the y-velocity.
Q11)
Describe the shape of the graph?
Q12)
What does the shape of the graph tell you about the motion in the y-direction?
Q13)
Use the linear regression button to add a best fit line to the graph. Record the equation given by the fit.
Q14)
What does the slope you recorded in Q13) tell you?
Q15)
Does your answer to Q12) agree with your answer to Q9)?
Print and attach the graph.
5.
View the graph of y-position vs. x-position
Q16)
Describe the shape of the graph.
Q17)
Use the curve fit button to add a best fit quadratic to the
graph. Record the equation given by the
fit.
E18)
You can also determine this equation from your fits to the x-position
and the y-position. Solve the equation
you recorded in Q3) for the time. Then
substitute that expression for t in the equation you recorded in Q10). Once you’ve collected like terms you have an
equation for the trajectory of the ball.
Show your work in the space below.
Q19)
How does the equation you found in E18) compare to the fit you found in
Q17)?
Summary Questions
S20)
Fill in the blanks with either uniform
or accelerated. In projectile motion the motion in the
x-direction is ____________ and the motion in the y-direction is ___________.
S21)
What is the acceleration in the x-direction for projectile motion?
S22)
What is the acceleration in the y-direction for projectile motion?
S23)
Circle the correct answer. In
projectile motion, the motion in the x-direction is uniform/free fall.
S24)
Circle the correct answer. In
projectile motion, the motion in the y-direction is uniform/free fall.