part 1. motion of objects projected horizontally
TRANSCRIPT
![Page 1: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/1.jpg)
Part 1.Motion of Objects Projected
Horizontally
![Page 2: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/2.jpg)
Introduction
Projectile Motion:
Motion through the air without a propulsion Examples:
![Page 3: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/3.jpg)
Projectile Motion
Keep it simple by considering motion close to the surface of the earth for the time being
Neglect air resistance to make it simpler
![Page 4: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/4.jpg)
Projectiles A projectile has only one
force acting upon - the force of gravity
Examples: golf, soccer ball, bullet, rock dropped, javelin thrower …
![Page 5: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/5.jpg)
Factors Influencing Projectile Trajectory
Trajectory: the flight path of a projectile
Angle of projection Projection speed Relative height of
projection
![Page 6: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/6.jpg)
Factors Influencing Projectile Trajectory
Angle of Projection General shapes
Perfectly verticalParabolicPerfectly horizontal
Implications in sports Air resistance may
cause irregularities
![Page 7: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/7.jpg)
Factors Influencing Projectile Trajectory
Projection speed:Range:
horizontal displacement. For oblique projection angles, speed
determines height and range For vertical projection angle, speed
determines height.
![Page 8: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/8.jpg)
Factors Influencing Projectile Trajectory
Relative Projection Height:Difference between
projection and landing height
Greater the relative projection height, longer the flight time, greater the displacement.
![Page 9: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/9.jpg)
Projectile Motion
The path (trajectory) of a projectile is a parabola Describe the motion of an object in TWO
dimensionsVertical - vY
Horizontal - vX
Horizontal and vertical motion are independent (90°)
![Page 10: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/10.jpg)
Projectile Motion
HorizontalMotion of a ball rolling freely along a level surfaceHorizontal velocity is ALWAYS constantThe horizontal component of it’s velocity does not
change. vX is constant
![Page 11: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/11.jpg)
Projectile Motion
VerticalMotion of a freely falling objectForce due to gravityVertical component of velocity changes with time
![Page 12: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/12.jpg)
Package drop The package follows a parabolic path and remains directly below the
plane at all times The vertical velocity changes (faster, faster) The horizontal velocity is constant!
![Page 13: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/13.jpg)
Trajectory and Range Maximum range
is at 45° Low and high
trajectory cover the same distance.
30 and 60 10 and 80 25 and…
![Page 14: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/14.jpg)
![Page 15: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/15.jpg)
The path (trajectory)of a projectile is a parabola
Parabolic motion of a projectile
![Page 16: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/16.jpg)
v0
x
y
![Page 17: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/17.jpg)
x
y
![Page 18: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/18.jpg)
x
y
![Page 19: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/19.jpg)
x
y
![Page 20: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/20.jpg)
x
y
![Page 21: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/21.jpg)
x
y
•y-motion is accelerated
•Acceleration is constant, and downward
• a = g = -9.81m/s2
•The horizontal (x) component of velocity is constant
•The horizontal and vertical motions are independent of each other, but they have a common time
g = -9.81m/s2
![Page 22: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/22.jpg)
ExperimentWhat do you think? Which ball will hit the ground first?
a) The left ball will hit firstb) The right ball will hit firstc) They will hit the ground at the same time.
![Page 23: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/23.jpg)
Projectiles
![Page 24: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/24.jpg)
Both balls hit the ground at the same time. Why?
As soon as both balls are released by the launcher, they are in "freefall.
The only force acting on both objects is gravity.
Both objects accelerate at the same rate, 9.8m/s2
Both objects covering the same distance at the same rate and therefore hit the ground at the same time
![Page 25: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/25.jpg)
Equations
X- Component
Y- Component
€
Δx = vxi
Δt
€
Δy = vyiΔt +1
2at 2
vyf2 = vyi
2 + 2aΔy
vyf = vyi − at
Note: g= 9.8 m/s^2
![Page 26: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/26.jpg)
ANALYSIS OF MOTION
ASSUMPTIONS:
• x-direction (horizontal): uniform motion
• y-direction (vertical): accelerated motion
• no air resistance
QUESTIONS:
• What is the trajectory?
• What is the total time of the motion?
• What is the horizontal range?
• What is the final velocity?
• What is the initial velocity?
![Page 27: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/27.jpg)
Example: Projectiles launched horizontallyWhat is the total time of the motion?What is the horizontal range?What is the final velocity?What is the initial velocity?
The Royal Gorge Bridge in Colorado rises 321 m above the Arkansas River. Suppose you kick a rock horiaontally off the bridge. The magnitude of the rock’s horizontal displacement is 45m How long does it take the rock to hit the ground? What speed did you have to initially have to kick the rock? How fast was the rock going before hitting the ground?
![Page 28: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/28.jpg)
Example: Projectiles launched horizontallyWhat is the total time of the motion?What is the horizontal range?What is the final velocity?What is the initial velocity?
People in movies often jump from buildings into pools. If a person jumps horizontally from the 10th floor(30m) to a pool that is 5m away from the building, how long does it take for him to hit the water in the pool? What initial speed must the person jump to make it? What is the final velocity of the person before he hits the water’s surface.
![Page 29: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/29.jpg)
Let’s try pg 99 practice D
![Page 30: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/30.jpg)
Board Work1.Erica kicks a soccer ball 12 m/s at horizontally from the edge of the roof of a building which is 30.0 m high.2. A ball thrown horizontally from the roof of a building lands 36m from the base of the building. Just before impact the ball had a velocity of 25m/s.3. A boy kicked a can horizontally from a 6.5 m high rock with a speed of 4.0 m/s. 4.A car drives straight off the edge of a cliff that is 54 m high. The police at the scene of the accident note that the point of impact is 130 m from the base of the cliff.
![Page 31: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/31.jpg)
Part 2.Motion of objects projected at an
angle
![Page 32: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/32.jpg)
vi
x
y
θ
vix
viy
Initial velocity: vi = vi [Θ]
Velocity components:
x- direction : vix = vi cos Θ
y- direction : viy = vi sin Θ
Initial position: x = 0, y = 0
![Page 33: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/33.jpg)
x
y
• Motion is accelerated
• Acceleration is constant, and downward
• a = g = -9.81m/s2
• The horizontal (x) component of velocity is constant
• The horizontal and vertical motions are independent of each other, but they have a common time
a = g =
- 9.81m/s2
![Page 34: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/34.jpg)
ANALYSIS OF MOTION:
ASSUMPTIONS
• x-direction (horizontal): uniform motion
• y-direction (vertical): accelerated motion
• no air resistance
QUESTIONS
• What is the trajectory?
• What is the total time of the motion?
• What is the horizontal range?
• What is the maximum height?
• What is the final velocity?
![Page 35: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/35.jpg)
Equations of motion:
X
Uniform motion
Y
Accelerated motionACCELERATION ax = 0 ay = g = -9.81 m/s2
VELOCITY vx = vi cos Θ vy = vi sin Θ + a t
DISPLACEMENT Δx = vi cos Θ t Δy = vi sin Θ t + ½ a t2
![Page 36: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/36.jpg)
Equations
X- Component
Y- Component
€
Δx = vicosθΔt
€
Δy = (v i sinθ)t +1
2at 2
vyf2 = (v i sinθ)2 + 2aΔy
vyf = (v i sinθ) − at
![Page 37: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/37.jpg)
Example: Projectiles launched @ an angle
Erica kicks a soccer ball 12 m/s at an angle of 40 degrees above the horizontal.
*Don’t forget to draw your chart*
What are the x and y components of the vi?
How long does it take the ball to hit the ground?
What is the max height the ball travels?
How far does she kick the ball?
![Page 38: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/38.jpg)
Example: Projectiles launched @ an angle
An archer needs to be sure to shoot over the wall of the castle. He raises his bow at an angle of 65° and fires his arrow with an initial velocity of 43m/s.
*Don’t forget to draw your chart*
What are the x and y components of the vi?
How long does it take the arrow to hit the ground?
What is the max height the arrow travels?
How far does the archer shoot the arrow?
![Page 39: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/39.jpg)
Projectile Motion – Final Equations
Trajectory Parabola, open down
Total time Δt =
Horizontal range Δx =
Max height hmax =
(0,0) – initial position, vi = vi [Θ]– initial velocity, g = -9.81m/s2
2 vi sin Θ
(-g)
vi 2 sin (2 Θ)
(-g)
vi2
sin2 Θ
2(-g)
![Page 40: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/40.jpg)
PROJECTILE MOTION - SUMMARY Projectile motion is motion with a constant
horizontal velocity combined with a constant vertical acceleration
The projectile moves along a parabola
![Page 41: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/41.jpg)
The monkey and the zookeeper!! A golfer practices driving balls off a cliff and into
the water below. The dege of the cliff is 15m above the water. If the golf ball is launched at 51m/s at and angle of 15°, how far does the ball travel horizontally before hitting the water?
![Page 42: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/42.jpg)
The monkey and the zookeeper!! A zookeeper finds an escaped monkey hanging
from a light pole. Aiming her tranquilizer gun at the monkey, she kneels 10m away from the light pole, which is 5m high. The tip of her gun is 1m above the ground. At the same moment that monkey drops a banana, the zookeeper shoots. If the dart travels at 50m/s, will the dart hit the monkey, the banana, or neither one?
![Page 43: Part 1. Motion of Objects Projected Horizontally](https://reader036.vdocuments.us/reader036/viewer/2022081420/5515a4ea55034674578b6069/html5/thumbnails/43.jpg)
PROJECTILE MOTION - SUMMARYReview for Test 2 Pg 109 # 2, 3, 6, 12, 13, 14, 15, 17, 18, 20, 21, 24,
25, 27, 28, 30, 31, 32, 34, 37 Pg 69 # 18, 20, 22, 24, 26, 30, 31, 33, 35, 38, 39,
46