How do you know something is moving? Question: How do you know something is moving?

Measuring Motion

I. Observing Motion A. To observe motion, you need a reference point – a stationary object. Reference Point

Displacement – change in position School Displacement – change in position Wal-Mart Displacement also has DIRECTION. Home

d v t distance time (m/s) speed = B. Speed – how fast an object moves. * 07/16/96 B. Speed – how fast an object moves. 1. Rate of motion d Distance traveled per unit of time v t distance time (m/s) speed = *

Total distance Total time Average speed = * 07/16/96 3. Instantaneous Speed – speed at a given instant 4. Average Speed: Total distance Total time Average speed = *

Problem A bicycle rider has traveled 60 meters over the past 30 seconds. What is the average speed? Given Work d = 60 m t = 30 seconds v = ? d t v = 60m 30 s d v = = 2m/s v t

Problem A motorcycle travels at a speed of 100km/h for 2 hours. How far does she travel? Given Work d = ? t = 2 hr v = 100 km/hr d = v x t d =(100 km/hr)(2hr)= d 200 km v t

Problem d v t How long will it take a person walking 2 m/s to travel 2000 meters? Given Work d = 2000 m t = ? v = 2 m/s d v t = 2000 m 2 m/s d t = = 1000 s v t Around 16 minutes