Projectile Motion : Projectile Motion
What is a projectile? : What is a projectile? Any object that moves through the air or space
First… : First… Let’s think about objects that move in a straight line…
Horizontal Motion : Horizontal Motion If there were no gravity, an object moving horizontally (in the x-direction) would continue to move _________________ in a straight line
Vertical Motion : Vertical Motion If an object is dropped vertically (in the y-direction), then _________ causes it to _______________ downwards gravity accelerate
Projectile Motion : Projectile Motion Projectile motion is a ________________!
In the x-direction, it continues to move at a __________ speed, but in the y-direction, it ___________downwards because of gravity! combination constant accelerate
Take-Home Message!!! : Take-Home Message!!! For a projectile: THE X-VELOCITY IS _________________ OF THE Y-VELOCITY!!!
The speed in the x-direction doesn’t care what the speed in the y-direction is! INDEPENDENT
Why? : Why? Remember that _____________is only pulling in one direction (__________!) and nothing is pulling ________________
If there were no gravity, a projectile would go _____________forever: gravity down right or left straight
Velocity Vectors : Velocity Vectors Remember that velocity has a ____________, so it can be represented using ____________!
We can break down the velocity into separate x- and y- components: direction vectors
Velocity Vectors : Velocity Vectors Let’s examine the x and y velocity vectors for a projectile:
Its x-velocity stays __________and its y-velocity _____________. constant increases
Y-Velocity : Y-Velocity Just like in free-fall:
Velocity in the y-direction ___________on the way up, and ____________on the way down
At the top of the path, the y-velocity is always ______
Velocity on the way up ________velocity on the way down when you reach the same _________ decreases increases zero equals height
*Checkpoint Question 1* : *Checkpoint Question 1* If you were walking at a constant velocity with a baseball and threw it up into the air while you were walking, would it fall
A. in front of you
B. behind you
C. right back into your hands?
Why??
Answer! : Answer! Its y-velocity is different than yours, but its x-velocity stays the same as you. It should land back into your hands!
**Checkpoint Question 2** : **Checkpoint Question 2** An airplane is carrying a bomb and traveling with a velocity of 1,100 mph east. If it releases its bomb and continues at that velocity, will the bomb land:
A. Directly underneath the plane
B. Behind the plane
C. Ahead of the plane
Answer! : Answer! If they’re going at the same x-velocity, it will land directly beneath the plane!
***Checkpoint Question 3*** : ***Checkpoint Question 3*** Suppose two balls released from the same height: one is dropped from rest, and the other is thrown horizontally. Which will hit the ground first? Why?
They will hit at the same time, because they are both being pulled by gravity at the same rate! Only one will have a greater x-range.
X-Range and Max Vertical Height : X-Range and Max Vertical Height Your x- distance is called your __________and your y-distance is called your __________.
Your range and height depend on:
The _______ that the projectile is launched at and
The __________it is launched at range height angle velocity
Angle : Angle Increasing your angle increases your range until you reach 45°.
45° to 90°, increasing your angle decreases your range.
Initial Velocity : Initial Velocity The greater the initial velocity of a projectile, the ____________it will go: farther
The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. : The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. Earth
The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. : The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. Earth Small horizontal velocity
The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. : The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. Earth Medium horizontal velocity
The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. : The trajectory of an object depends on how fast it is moving horizontally and how long gravity acts on it for. Earth Fast horizontal velocity
Projectile Motion : Projectile Motion A projectile is always falling.
The faster it moves horizontally, the farther away it will be when it hits the ground. Slow Medium Fast