Ch+2+Sec+5+KirnumB

Section 5
What do you think? Being launched from the ground at different angles changes where the object lands. A greater launch speed causes an object to move faster

Physics Talk
 * Modeling Projectile Motion
 * Motion
 * Constant speed along a straight line
 * corresponds to the amount of launch speed and its direction
 * Downward acceleration at 9.8 m/s^2
 * caused by the Earth's gravitational force
 * takes effect immediately upon launch
 * Models
 * Mathematical model- the table of times, speeds, and distances during falling
 * Physical model- the evenly spaced strings calculated lengths
 * All balls travel in parabolas
 * The 45 degree launch produces the greatest rage
 * Distance traveled at pairs of aneles (30 and 60, 20 and 70, 10 and 80...) are identical
 * Complementary angles of a ground to ground launch have the same ranges
 * not the same TIME, same distance (horizontal)
 * Small angles have greater horizontal velocity but are in the air a short time
 * Large angles have smaller horizontal velocities but are in the air a long time

Checking up 1. Two types of motion that help you understand the trajectory of a projectile are constant speed and downward acceleration. 2. The fundamental requirement a scientist must meet when proposing a model of some natural phenomenon is that the model must match reality in nature. 3. Small angles have greater horizontal velocity but are in the air a short time while large angles have smaller horizontal velocities but are in the air a long time.

PTG 1. 45 Degree angles produce the greatest range because they travel the furthest. 2. a) If the launch angle is greater then 45 degrees, it is more __b) If it is greater then 45 degrees,__ it is less 3. a) 60 b) 75 4. They aren't trying to get the farthest range, they divers want to hit the water at a smaller angle 5. He knew how to time his jump to provide him with a 45 degree jump, giving him a wide range 6. a) It has none b) to the left 7. 29.4 m/s 5 m/s 15 m 8. 30 or 60 degrees 9. The one with the angle closest angle to 90 degrees 10. a) down b) 4.5 s c) 90 m

What Do you think now? The angle of the trajectory determines the distance the object travels; at 45 degrees, the object has the longest range.