10-15 minutes to work on finishing the trajectory problems (then go over a few of them)
TRANSCRIPT
![Page 1: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/1.jpg)
![Page 2: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/2.jpg)
![Page 3: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/3.jpg)
Projectile Motion (Physics of Bullets)Describes the motion of an object in
TWO dimensionsNeglect air resistance to make it
simpler
![Page 4: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/4.jpg)
Projectile Motion
The ball is in free fall vertically and moves at constant speed horizontally!!!
![Page 5: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/5.jpg)
•Every moving object has horizontal & vertical velocity.
•Vertical velocity is changed by force of gravity.
•Horizontal velocity stays the same.
![Page 6: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/6.jpg)
Projectile Motion•As a cannon is fired upward, the horizontal velocity stays the same.
•Gravity causes the bullet to arc (which creates the parabola)
![Page 7: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/7.jpg)
![Page 8: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/8.jpg)
•The angle of firing affects the path of the bullet over a period of time.
![Page 9: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/9.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
Gun Pointing Up
Gun Pointing Down
![Page 10: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/10.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
y height of victim / wound (m)y0 height of shooter’s location (m)v0 initial speed of the bullet (m/s)θ angle of firingt time for bullet to travel (s)g acceleration due to gravity (always 9.8m/s2)
Gun Pointing Up
Gun Pointing Down
![Page 11: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/11.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
y height of victim / woundy0 height of shooter’s locationv0 initial speed of the bulletθ angle of firingt time for bullet to travelg acceleration due to gravity (always 9.8m/s2)
Gun Pointing Up
Gun Pointing Down
Height of Shooter
How height is affect by vertical velocity
How height is affect by gravity
![Page 12: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/12.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
1. A sharpshooter is located in a tree. The sharpshooter fires down at a 30 degree angle. It takes the bullet 0.5s to hit the victim’s shoulder at 1.2m high. The speed of the bullet was 62m/s. How high up is the sharpshooter?
1.2 = y0 - 62sin(30)x(0.5) – (0.5)(9.8)(0.5)2
1.2 = y0 – 15.5 – 1.2251.2 = y0 – 17.725
18.925m = y0
![Page 13: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/13.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
2. A sharpshooter is located in a tree 15m tall. The sharpshooter fires down at a 25 degree angle. It takes the bullet 0.5s to hit the victim’s shoulder (located at 1.5m high). What is the speed of the bullet as it leaves the gun?
1.5 = 15 - v0sin(25)x(0.5) – (0.5)(9.8)(0.5)2
1.5 = 15 – 0.211v0– 1.225-12.275 =-0.211v0
58.2m/s =v0
![Page 14: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/14.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
3. A sharpshooter fires a gun from the ground at a height of 2.0m and angle of 45degrees up. It takes the bullet 1.2s to hit the victim located in a building 120m high. What is the speed of the bullet as it leaves the gun?
120 = 2.0 + v0sin(45)x(1.2) – (0.5)(9.8)(1.2)2
120 = 2.0 + 0.849v0– 7.056125.056 =0.849v0
147.3m/s =v0
![Page 15: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/15.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
4. A sharpshooter is located in a tree 25m tall. The tree is located 15m away from the victim. It takes the bullet 0.1s to hit the victim’s shoulder (located at 1.2m high). What is the speed of the bullet as it leaves the gun?
1.2 = 25 - v0sin(θ)x(0.1) – (0.5)(9.8)(0.1)2
1.2 = 25 – 0.1v0sin(θ)– 0.049-23.751 =-0.1v0sin(θ)
277.1m/s=v0
-23.751 =-0.1v0sin(59) = -0.1x0.857v0
![Page 16: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/16.jpg)
200
200
2
1)sin(
2
1)sin(
gttvyy
gttvyy
1. Get into your ballistic lab groups.2. Show me the pre-lab (EVERYONE IN THE GROUP) and
get it approved.3. Pick up your supplies (EVERYone MUST WHERE
GOGGLES).4. Collect your data & make observations.5. Cleanup and put all materials away.
*When done, you can work on your projectile motion practice problems!
![Page 17: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/17.jpg)
A. For each trial of data, calculate the initial speed of the gun. Find an average for the initial speed (v0). (Be sure to show your work!)
B. Use the trajectory method to calculate where the bullet should have hit (height-wise) for each trial.
C. What were some observations you made during the trials?D. Did your results match what you had expected? Why/why not?E. What are some factors that could have affected the outcome of your
results? Explain these factors.
![Page 18: 10-15 minutes to work on finishing the trajectory problems (then go over a few of them)](https://reader036.vdocuments.mx/reader036/viewer/2022062315/56649ebd5503460f94bc6846/html5/thumbnails/18.jpg)
I. Background (Background on anatomy of a gun, how a gun fires, what affects a bullet’s path) (5pts)
II. Purpose (2.5pts)III. Experimental Setup (IV, DV, Control, Extraneous Variables)
(2.5pts)IV. Procedures (no I, we, or you.) (5pts)V. Data Table (5pts)VI. Analysis (MUST BE WELL DEVELOPED) (20pts)VII.Conclusion (review purpose of lab, whether results were expected,
what errors occurred, and how to make this lab more accurate) (5pts)
VIII. Attached: all the lab data sheets/prelab papers (5pts)