Describing Motion Motion Speed & Velocity Motion & Forces Describing Motion Motion Speed & Velocity

Newton’s First Law Newton’s First Law of Motion

Motion Problem: Is your desk moving? We need a reference point...

Motion Motion - Reference point Motion

Relative Motion .

Motion Distance .

Motion Displacement . . Example – What is your displacement in a school day ?

Motion Displacement is the distance and direction of an object's change in position from a reference point. Suppose a runner jogs to the 50-m mark and then turns around and runs back to the 20-m mark. The runner travels 50 m in the original direction (north) plus 30 m in the opposite direction (south), so the total distance she ran is 80 m.

Motion Problem: You are a passenger in a car stopped at a stop sign. Out of the corner of your eye, you notice a tree on the side of the road begin to move forward. .

s d t Speed & Velocity Speed .

Calculating Speed .

Calculating Speed

Speed & Velocity Instantaneous Speed . Average Speed

Changing Instantaneous Speed When something is speeding up or slowing down, If an object is moving with constant speed, To determine direction you need to know the velocity

Speed & Velocity Problem: A storm is 10 km away and is moving at a speed of 60 km/h. Should you be worried? .

Speed & Velocity Velocity .

t d s Calculations d = 100 m s = t = 20 s s = ? GIVEN: WORK: Your neighbor skates at a speed of 4 m/s. You can skate 100 m in 20 s. Who skates faster? GIVEN: d = 100 m t = 20 s s = ? WORK: s = s d t

t d s Calculations s = 330 m/s t = d = 1km = 1000m t = ? WORK: GIVEN: Sound travels 330 m/s. If a lightning bolt strikes the ground 1 km away from you, how long will it take for you to hear it? GIVEN: s = 330 m/s d = 1km = 1000m t = ? WORK: t = s d t

Graphing Motion slope = steeper slope = Straight line = flat line + * 07/16/96 Graphing Motion slope = steeper slope = Straight line = flat line + Single point = Distance-Time Graph A B *

Graphing Motion Who started out faster? . Who had a constant speed? Describe B from 10-20 min. Find their average speeds. Distance-Time Graph A B

Graphing Motion Distance-Time Graph . Changing slope =

Graphing Motion Specify the time period when the object was... slowing down . speeding up moving at a constant speed not moving Speed-Time Graph