DAY 16 LETS BEGIN! TODAY AT A GLANCE: 1) We look at why movie directors need physics classes 2) We learn some concepts 3) I lead you into how to do projectile math 4) You try one on the boards to show you get it 5) We drop the seasonal cheer 6) We graph the seasonal cheer and solve it!

Kinematics, concepts, graphs FIRST OF ALL…THE QUIZ. Kinematics, concepts, graphs

WATCH THE FOLLOWING What is wrong with the physics in this video?

TOPIC THREE! PROJECTILES, 2-D MOTION! The Idea: Is gravity a pull in both X and Y directions? NO! So gravity only affects the Y direction, it has no effect on the X direction! So in the air, the X velocity is constant, since gravity won’t speed it up or slow it down. But TIME is the same in X and Y

VOTING! I am going to throw 2 balls horizontally at the same time. One thrown slow, one thrown fast. Which will hit first… A) Slower B) Faster C) Same time

What could I have done to make them not hit at the same time?

Watch The Following THIS VIDEO! Which explanation is correct? A) In the air the pull of gravity made the ball come back to its start point B) The shot straight up did not affect the balls forward motion, which stayed the same C) The carts forward velocity was given to the ball, so it ended back in the cart D) The shot went up, which meant it took the same time to come down, which does not affect its movement forward

I SHOW You find a dwarf panda about to jump horizontally off a table onto a pillow below. The pillow it wants to hit is 120cm from the base. The table is .75m tall. What is the magnitude of the velocity it rolled off at?

Our strategies 1) Separate info into their X and Y parts 2) Acceleration in ‘Y’ is 10m/s2 downwards, ‘X’ is 0m/s2 . So X velocity does not change. 3) The phrase ‘Horizontal’ means only in X, so if it starts horizontally then Vy initial is 0. 4) The time is the same for X and Y. Usually solved for. 5) Solve for the required info for X and Y.

YOU TRY…on the boards A car drives off a bridge horizontally at 15m/s. The car was in the air for 3 seconds. How far did the car land from the base of the bridge? How high up is the bridge? Does it hit the water at a final velocity of zero?

PUMPKIN SPICE! I will shove a pumpkin off THS horizontally. Goal: To find the initial velocity of the pumpkin, and how high THS is. As a class, you will have: Metersticks and stopwatches. Start by drawing a picture in your notebook of each ones path from the same point, and make an X and Y chart FOR EACH… BUT FIRST

PRE QUESTIONS 1) Will the X (forward) velocity of the pumpkin increase/decrease/not change while its in the air? 2) Will the Y (vertical) velocity of the pumpkin increase/decrease/not change while its in the air?

SOLVE IT FROM THE BOARDS Set up each equation: X and Y.

LETS DO THE GRAPHS