1. Motion in 2D
Chapter 6

2. 6.1 Projectile Motion
Projectile – object shot, launched, kicked, thrown, etc through the air
Path is up then down in curve
Called trajectory
Forces?
Force of earth and air resistance
Initial force causing motion
When known, can calculate trajectory

3. Independence of Motion in 2D
Objects fall at the same rate
Dropped compared to launched (vertically)
Myth Busters clip
Can separate motion
Motion in x-direction and motion in y-direction
Independent of each other

4. Launched at Angle
Symmetric
Range
Flight time or Hang time

5. 6.2 Circular Motion Change in direction leads to acceleration
Uniform Circular Motion
Constant speed around circle with fixed radius
Position vector length doesn’t change

6. Centripetal Acceleration
Velocity direction changes, but length is constant
Tangential to circle
Acceleration points in same direction as velocity change
Centripetal means center seeking

7. Centripetal Acceleration
Pg derivation
Period – time needed for object to make a complete revolution
Newton’s Second form
Net force always points toward center of circle
Net centripetal force

8. “Centrifugal Force” Centrifugal – outward force Nonexistent Fictitious
Actually inertia described by Newton’s 1st Law

9. 6.3 Relative Velocity Albert Einstein and his Theory of Relativity
Motion relative to a moving object and seen by stationary observer
Vice versa

10. Lab
Catapult lab