In this virtual laboratory you will investigate projectile motion with and without air resistance. You will find the maximum range of a football with given initial velocity and the launch angles required for it to hit a target.
Go to Canvas, Assignments, Extra Credit 3. Use the simulation to help you answer questions 1 - 5.
Procedure:
Open the Projectile Motion simulation.
Position the canon 20 m to the left of the target, as shown below. Make sure the cross on the canon is at the same height as the target. The ruler should lie on the horizontal axis of the coordinate system show.
Choose the football projectile and
give it an initial speed of between 14 and 18 m/s.
(a) Given the initial speed there are two launch
angles for the football to hit the center of the target.
What is the smaller of these launch angles (within ~±1^{o})?
(b) Given an initial speed there are two launch angles
for the football to hit the center of the target.
What is the larger of these launch angles (within ~±1^{o})?
(c) Given the initial speed, find the maximum range of the projectile
along the horizontal ruler.
Measure this distance with the ruler, do not
use the number displayed by the simulation. The simulation displays
the distance traveled by the ball before it hits the ground.
(d) Now set initial speed of the
projectile at 20 m/s. Find the maximum range of the
projectile along the horizontal ruler. For this maximum range note the launch angle and the hang
time of the football and estimate the maximum height of the football
above the ground during its flight.
Do this twice, once neglecting air resistance and once not neglecting air
resistance For the second case choose the drag coefficient to be 0.5.
Fill in the table below. Compare your results with and without air
resistance.
Projectile speed: 20 m/s | ||||
---|---|---|---|---|
Maximum range | Launch angle (deg) | Maximum height (m) | Hang time (s) | |
no air resistance | ||||
drag coefficient 0.5 |