1. Physics
Unit 6 2D Motion Key ideas

2. The vertical component is accelerated
Free fall
Gravity only

3. Horizontal component is constant

4. Projectiles experience a net downward force due to gravity

5. U6 Review #4 Need to find dx dy = ½ g t2 to find time to be 0.55s
Now substitute into dx=vt
Range is 2.74m
Skip 4b

6. U6 Review #8 Only gravity is acting on the object- always! Velocity:
Vy at top =0
Vx is always constant!
Acceleration is always 10 m/s/s but acting down

7. U6 Review #9
Both spheres will be in the air the same amount of time but the 5 m/s sphere will land further away
Remember the bullet fired vs bullet dropped?

8. #9 continued
Also, remember that each sphere, or any object for that matter, is affected in the vertical direction with dy=1/2gt2. If both objects fall from the same height, regardless of horizontal velocity (even if it’s 0), they fall in the same amount of time from the same height.
Range will be different because of dx=vt. Velocity in the horizontal is different, but since time is the same, the range, or dx, will be different.

9. U6 Review #10 and 11
In both situations remember how the horiz and vert velocity components change/don’t change
Horiz is always constant and the object will always be positioned above/below the moving object (snowmobile/plane/truck/person, ect)
#10- in the snowmobile
#11 lands directly below plane

10. One more
Fire a bullet horizontally and it hits the ground 1 second later. If you fire it twice the speed in the same direction, how long would it take to hit the ground?
Think about the penny flick/mythbusters
Similar situation to #9.
Use the PhET simulator to help you understand this.