1. Unit 1 MOTION

2. MOTION LINEAR MOTION Rate: a quantity divided by time Motion is relative Speed: rate at which distance is covered; how fast something is moving. Units: kilometer per hour: km/h; meters per second: m/s; miles per hour: mi/h “per” means divided by Instantaneous speed: speed at any instant Average speed= total distance covered time interval Average vs. Instantaneous Speed Page #13 Questions 1&2

3. Velocity: speed in a given direction Ex. A car travels at 60km/h to the north Constant velocity- requires constant speed (does not move faster or slower) and constant direction (motion in a straight line). Changing velocity: either the speed or direction (or both) is changing. What are the three controls used in a car to change the velocity?

4. Acceleration: rate at which velocity changes Acceleration= change of velocity time interval Applies to decreases as well as increases in speed. Also applies to changes in direction. Changing either speed or velocity, or both, changes velocity and we accelerate. If velocity is constant, acceleration is zero Acceleration

5. Free fall: only gravity affecting a falling object How fast: (speed or velocity) Elapsed time: time passed since the beginning of the fall Acceleration due to gravity (g) = 10m/s 2 v= gtv: instantaneous speed g: acceleration due to gravity t: time How far: (distance) d= ½ gt 2 d: distance traveled g: acceleration due to gravity t: time For an object thrown upward, the acceleration during the upward motion is the same as during the downward motion.

6. Air resistance- can noticeably affect the motion of objects like paper and feather but has less effect on more compact object like stones and baseballs. Ex. 1 A cheetah can maintain a constant speed of 25 m/s. How far will it travel in 10 seconds?

7. Ex. 2 An object falls freely from rest for 8 seconds. What is the instantaneous speed and distance fallen? CW answer question p22 # 1-22 (except 14,16,19)

8. Ex. 3 The peregrine falcon is the fastest known bird and has been clocked diving downward toward its prey at constant vertical velocity of 97.2 m/s. If the falcon dives straight down from a height of 100.m how much time does this give a rabbit below to consider his next move as the falcon begins to descent?