# Unit 4 – Lecture 3. Distance Distance – the length traveled by an object Practice – What is the distance? Pattie walks 4 km North, then 3 km East Joe.

## Presentation on theme: "Unit 4 – Lecture 3. Distance Distance – the length traveled by an object Practice – What is the distance? Pattie walks 4 km North, then 3 km East Joe."— Presentation transcript:

1 Unit 4 – Lecture 3

2 Distance Distance – the length traveled by an object Practice – What is the distance? Pattie walks 4 km North, then 3 km East Joe runs 30 m East, then runs 40 meters West Aaron jogs 4 km East, 4 km North, 4 km West, and 4km South Answers: 7 km ; 70 meters ; 16 km

3 Distance vs. Displacement Distance – length Displacement – distance AND direction of a movement from the starting point

4 Displacement If an object moves in a single direction, the displacement equals the distance + the direction start here 4 kmtotal displacement = 4km North

5 Displacement If an object moves in two opposing directions, the displacement is the difference between the two. start here 3 km 4 km total displacement = 4 km North + -3 km South = 1 km North (of original starting point) total distance = = 7 km Displacement can be positive or negative. A negative direction can be either the opposite of the original movement, or can follow the sign of a typical graph [North/East vs South/West]

6 Displacement – contd If an object moves in two directions, a triangle will be formed. If the angle is 90 º, use a 2 + b 2 = c 2 to solve. start here 4 km 3 km displacement

7 Displacement – contd If an object moves in two directions, a triangle will be formed. If the angle is 90 º, use a 2 + b 2 = c 2 to solve. start here 4 km 3 km 5 km displacement = = c 2 c 2 = (16) + (9) = 25 c 2 = (25) c = 5km

8 Displacement – contd Displacement can be given in: units with direction example: x number of meters North 30 meters East + 40 meters West displacement = 10 meters West

9 Displacement – contd Displacement can be given in: positive or negative units [like on a graph] positive = North {up} or East {right} negative = South {down} or West {left} 30 meters east + 40 meters west = 30 meters + (-40) meters = -10 meters

10 Displacement Practice – What is the displacement? Pattie walks 4 km North, then 3 km East 5 km displacement Joe runs 30 m East, then runs 40 meters West 10 meters [or -10] displacement Aaron jogs 4 km East, 4 km North, 4 km West, and 4km South 0 meters displacement go to website!!!!

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