Chapter2Section4

=__**Chapter 2 Section 4**__=

__**Learning Outcomes**__

 * apply the terms free fall, projectile, trajectory, and range
 * provide evidence concerning projectiles launched horizontally from the same height at different launch speeds (including zero launch speed).
 * explain the relationship between the vertical and horizontal components of a projectile's motion
 * recognize the factors that affect the range of a projectile
 * infer the shape of a projectile's trajectory

__**What Do You See?**__

 * the boy is timing which apple will take longer to fall
 * the girl is dropping one apple straight down and the other apple has a curve in it

__**What Do You Think?**__
(has to be a completely horizontal 90 degree launch) -because they are at the same height they will hit at the same time (they are falling so the only thing acting on them is gravity)
 * What determines how far an object thrown into the air travels before landing?**
 * mass does not impact it
 * the force, air resistance, and point at which the object is dropped will affect how far an object is thrown

__**Investigate**__
a. Do they hit the floor at the same time? -Yes they hit the floor at the same time because you only heard on sound as they hit. a. Do the coins hit the floor at the same or different times? (Hearing is the key to observation here, although you may wish to rely on sight as well.) -The coins always hit the floor at the same time as long as they are dropped from a 90 degree angle. a. Does the speed of the projected coin affect whether the two coins hit the floor at the same time? Explain your answer. -No they still hit the ground at the same time because gravity is the only thing that is affectin gthem. b. Does the speed of the projected coin change how far it lands horizontally from the coin that fell straight down? Explain your answer. -No because the pull of gravity determines when it will drop. c. Draw a single sketch that includes both the path of the coin that is falling and the coin that is projected. Imagine where each coin is at four identical points in time and note these predicted locations on your sketch. Label these times A, B, C,D. a. Do the coins hit the floor at the same or different times. -They hit the floor at the same time b. How does changing the height affect how far the projected coin travels horizontally as it falls? -It will fall differently, but still hit the ground the same time as the other coin.
 * Part A: Observe Two Coins Dropping**
 * 1. Hold two coins the same distance above the floor. Drop them at the same time. Listen to the sound they make as they strike the floor?**
 * 2.**
 * 3. Vary the speed of the projected coin.**
 * (in notebook)**
 * 4. Use a box, chair, or a stack of books to change the height from which you project the coins.**

1. a. I predict that I will be able to catch the ball because the ball will go with you as you toss it in the air. 2. b.Yes, when you throw the ball in the air you still catch it. The speed does not effect if you catch it or not.
 * Part B: Vertical and Horizontal Motion of a Projectile**

__**Physics Talk**__
-projectile: an object traveling through the air or other medium -a dropped coin and a horizontally thrown coin will hit the ground at the same time (when there is little to no air resistance) -the projected coin kept moving to the right, its vertical motion was identical to the dropped coin -the falling coin has no speed to the right in a perfect fall -the vertical motion does not affect the constant horizontal speed -closing your eyes and listening can prove that they hit at the same time because it only makes one noise rather than two. -The velocity is constantly changing because it slows down as it rises and speeds up as it falls. -the change in velocity of the call is always 9.8m/s every second of 9.8m/s^2
 * Projectiles and Trajectories**
 * Believing is Seeing**