Motion- Chapter 1 pp. 12-29

Speed- Speed = distance a measure of how fast something is moving. Equation- Speed = distance time

Use this to remember the equation! Units for speed- mi/h (mph) km/h or m/s ( / is read per and means divided by) Use this to remember the equation!

1.) What is the speed of a car that has gone 200 km in 4 hrs.?

Answer- 200km = 50 km/hr 4 hr

Acceleration- the rate of change in velocity Acceleration = change of velocity time interval

Units for Acceleration- km/hr2 Reads kilometers per hour per hour Each hour the speed changes so many kilometers per hour m/s2 Reads meters per second per second Each second the speed changes so many meters per second km/h/s Reads kilometers per hour per second Each second the speed changes so many kilometers per hour

3. ) A car can go from 0 km/h to 90 km/h in 10 s 3.) A car can go from 0 km/h to 90 km/h in 10 s. What is its acceleration?

Answer- 90 km/h – 0 km/h = 9 km/h/s 10 s These units are the hardest to understand! 4.) What do these units mean? This answer means that each second the car is speeding up 9 km/h

Free Fall (Vertical Velocity)- an object falling free of all restraints v = gt v- velocity g- acceleration of gravity 9.8 m/s2 on earth during each second of fall the object gains 9.8 m/s in velocity t- time

6. ) A person jumps out of an airplane and has been falling for 3 sec 6.) A person jumps out of an airplane and has been falling for 3 sec., how fast are they going? v = gt = 9.8 (3) = 29.4 m/s ?

Calculating Vertical Distance- Freely falling objects only Equation- d = ½ gt2 d = distance traveled Units- meters g = acceleration due to gravity Units- m/s2 t = time of fall Units- seconds

7. ) A person jumps off a cliff and has been falling for 1. 3 sec 7.) A person jumps off a cliff and has been falling for 1.3 sec., how far did they fall?

Answer: d = ½ gt2 d = ½ x (9.8) x (1.3)2 d = 4.9 x 1.69 d = 8.28 meters 7.) Why are the units meters? The units on 9.8 are m/s2.

Done!!