Chapter 11 Motion

11.1 Concepts Define motion What is required to describe motion completely How distance and displacement are different How to calculate displacement 11.1 Concepts

Physicists study laws that govern space, time, forces, motion, matter and energy. Motion (physics), any movement or change in position or time. Motion is governed by four universal forces: Gravitational forces Electromagnetic forces Strong nuclear forces Weak nuclear forces In order to describe motion, you must state the direction the object is moving as well as how fast the object is moving. To describe motion accurately and completely, a frame of reference is necessary. Motion

What is Frame of Reference The Frame of Reference determines how motion of an object is described. What is Frame of Reference

Distance and Displacement Measuring Distance Distance is the length of a path between two points. Distance is expressed in SI units of meters(m) Distance and Displacement

Distance and Displacement Measuring Displacement To describe an objects position relative to a given point, you nee to know how far away and in what direction the object is from that point. Displacement is the direction from the starting point and the length of a straight line from the starting to the ending point. Displacements are sometimes used when giving directions. They are examples of vectors. Distance and Displacement

Measuring Displacements To describe an object’s position relative to a given point, you need to know how far away and in what direction the object is from that point. Displacement provides this information.

Measuring Displacements Think about the motion of a roller coaster car. The length of the path along which the car has traveled is distance. Displacement is the direction from the starting point to the car and the length of the straight line between them. After completing a trip around the track, the car’s displacement is zero.

Combining Displacements How do you add displacements? A vector is a quantity that has magnitude and direction. Add displacements using vector addition.

Combining Displacements Displacement is an example of a vector. The magnitude can be size, length, or amount. Arrows on a graph or map are used to represent vectors. The length of the arrow shows the magnitude of the vector. Vector addition is the combining of vector magnitudes and directions.

Combining Displacements Displacement Along a Straight Line When two displacements, represented by two vectors, have the same direction, you can add their magnitudes. If two displacements are in opposite directions, the magnitudes subtract from each other.

Combining Displacements Add the magnitudes of two displacement vectors that have the same direction. Two displacement vectors with opposite directions are subtracted from each other.

If you walk across town, taking many turns, your displacement is the Assessment Questions If you walk across town, taking many turns, your displacement is the total distance that you traveled. distance and direction of a straight line from your starting point to your ending point. distance in a straight line from your starting point to your ending point. direction from your starting point to your ending point.

Assessment Questions You travel 30 miles west of your home and then turn around and start going back home. After traveling 10 miles east, what is your displacement from your home? 20 km 20 km west 40 km 40 km west

Chanice drives her scooter 7 kilometres north Chanice drives her scooter 7 kilometres north. She stops for lunch and then drives 5 kilometres east. What distance did she cover? What was her displacement? Practice 1

Anthony walks to the pizza place for lunch Anthony walks to the pizza place for lunch. He walk 1 km east, then 1 km south and then 1 km east again. What distance did he cover? What was his displacement? Practice 2

On his fishing trip Justin rides in a boat 12 km south On his fishing trip Justin rides in a boat 12 km south. The fish aren’t biting so they go 4 km west. They then follow a school of fish 1 km north. What distance did they cover? What was their displacement? Practice 3

Tara goes on a camel safari in Africa Tara goes on a camel safari in Africa. She travels 5 km north, then 3 km east and then 1 km north again. What distance did she cover? What was her displacement? Practice 4

Alex goes cruising on his dirt bike Alex goes cruising on his dirt bike. He rides 700 m north, 300 m east, 400 m north, 600 m west, 1200 m south 300 m east and finally 100 m north. What distance did he cover? What was his displacement? (use 1cm = 100m) Practice 5

Jose buys a new moped. He travels 3 km south and then 4 km east Jose buys a new moped. He travels 3 km south and then 4 km east. How far does he need to go to get back to where he started? Practice 6

What are two pieces of information required to accurately and completely describe motion? What SI unit is used in association with distance? A vector generally provides a direction and a ? When 2 vectors are in the same direction, they are __ to find displacement. Let’s Review

11.2 Speed and Velocity Section Concepts The students will be able to calculate speed and velocity using distance and displacement of vectors. 11.2 Speed and Velocity

What Is Speed?

What Is Velocity?

11.3 Acceleration