1. Principles of Technology Physics
Projectile Motion
Principles of Technology Physics

2. Curvilinear Motion Curvilinear motion is motion along a curved path.
Projectile motion is a special type of curvilinear motion. Any thrown object is in projectile motion.

4. Vertical and Horizontal Velocities of a Projectile
In projectile motion, vx (horizontal velocity) is constant and there is no acceleration in this direction.
The vertical velocity vy is not constant, it is accelerated downward due to gravity (9.8 m/s2).

7. Vertical and Horizontal Velocities of a Projectile
In the horizontal direction, equal distances are covered in equal amounts of time.
But in the vertical direction, there is acceleration, so different distances are covered in equal amounts of time.

10. Path of a Projectile Projectiles follow a parabolic trajectory.
Since the path is parabolic, if the launching and landing locations are at the same elevation, the time to get to the peak of the path is equal to the time to come down from the peak of the path and the launch velocity will be equal in magnitude to the landing velocity.

13. Projectile Motion Problems
Work all problems in two parts (horizontal and vertical).
For the horizontal part, the only equation that can be used is:

14. Projectile Motion Problems
For the vertical part, one of the following can be used:

15. Projectile Motion Problems
The only thing that can go between the horizontal and vertical parts is time.

16. Example Problem
A girl jumps off of a 10 m diving platform with a horizontal velocity of 2 m/s and hits the water 1.43 seconds later.
a) How far horizontally from the end of the platform does she hit the water?
b) What is her final velocity when she hits the water?

17. a) How far horizontally from the end of the platform does she hit the water?
Givens:
Formula:
Answer:
Work:
Unknown:
d = m
v = 2 m/s
t = 1.43 sec
2 m/s = ___d___
1.43 sec
d = (2 m/s)(1.43 sec)
d = ?

18. b) What is her final velocity when she hits the water?
Givens:
Formula:
Answer:
Work:
Unknown:
vf = m/s
vi = 0 m/s
t = 1.43 sec
g = 9.8 m/s2
vf = 0 m/s + (9.8 m/s2)(1.43 sec)
vf = ?

21. Launched at an Angle
The launch angle has an effect on the range of the projectile (distance travelled).

22. Launched at an Angle

23. Launched at an Angle
As the angle increases from 0 to 45 degrees, the range increases.
At 45 degrees, the range is at a maximum.
As the angle increases from 45 degrees to 90 degrees, the range decreases.