Notes for Frame of Reference, Distance & Displacement. Write these notes in your IAN.
What is a Frame of Reference? Well, have you ever been to the beach? What happens when you swim out in the water away from the shoreline? A Frame of Reference is how you see something happen from your perspective.
Is the speed of the ball different relative to the pitcher, the truck driver, and the jet pilot? Why or why not?
What is your definition of DISTANCE? Distance is the length of the actual path taken by an object to reach a destination. The variable for distance is “d”, and we will usually measure distance in meters, [m].
Distance (d) – how far an object travels. Does not depend on direction. Imagine an ant crawling along a ruler. What distance did the ant travel? d = 3 cm cm
Distance does not depend on direction. Here’s our intrepid ant explorer again. Now what distance did the ant travel? d = 3 cm Does his direction change the answer? cm
Distance does not depend on direction. Imagine our ant explorer changing his direction. What distance did the ant walk? d = 7 cm Does his direction matter? cm
What is your definition of DISPLACEMENT? Displacement is how far the object is from its starting point to its ending point, regardless of how it got there. This is a STRAIGHT LINE measurement. The formula for displacement is and displacement is also measured in meters, [m].
Find the displacement of the ant. Δx = x f – x i Distance: 7 cm Displacement: Δx = 3 [cm]– 0 [cm] = +3 [cm] What is the ant’s direction? cm
An athlete runs around a track that is 100 meters long three times, then stops. What is the athlete’s distance? What is the athlete’s displacement? Distance = 300 m Displacement = 0 m Why?