Presentation on theme: "Physics Unit 2 1-D and 2-D Motion Topics: 4 What is Linear Motion? 4 Vector vs. Scalar Quantities 4 Distance vs. Displacement (Comparison) 4 Speed vs."— Presentation transcript:
Topics: 4 What is Linear Motion? 4 Vector vs. Scalar Quantities 4 Distance vs. Displacement (Comparison) 4 Speed vs. Velocity (Comparison) 4 Velocity: Constant, Average, Instantaneous 4 Acceleration
Linear Motion 4 Motion in one direction 4 Example: the motion of a Marta train- the train moves either forward or backward along the track
SCALAR PHYSICAL QUANTITY Can be completely specified by its magnitude with appropriate units. It has no direction. Ex) Distance, time, speed, mass, etc.
PHYSICAL QUANTITY VECTOR Has a magnitude, a unit and a direction e.g displacement, velocity, acceleration, force.
Demonstrating a Vector The direction of the arrow indicates the direction of the vector quantity. The length of the arrow indicates the magnitude of the vector quantity. A Tail Head
ADDING VECTORS -ONE DIMENSIONAL 4 Vectors are added by placing the tail of one vector at the head of the other vector. 4 A third vector (C) is drawn by placing the tail of one vector at the head of the other. AB C
EXAMPLES 200m100 m 300 m-resultant 50 m 30 m 20 m-resultant
Distance vs. Displacement 4 Displacement- a change in position d = d f - d i final position - initial position
Displacement Questions 1. Amy runs 2 blocks south, then turns around and runs 3 miles north. 2. Jermaine runs exactly 2 laps around a 400 meter track. 3. Ray runs 30 feet north, 30 feet west, and then 30 feet south. 4. Jamison turns around 5 times. 5. David walks 3 km north, then turns and walks 4 km east.
Constant Velocity Graph 4 The velocity is equal to the slope of a distance versus time graph
Average Velocity 4 Used to describe an objects motion when the velocity is changing, i.e. speed up, slow down, stop, start, etc. 4 Average velocity will equal the magnitude of an object moving with a constant velocity.
Calculating Average Velocity 4 Total distance (displacement)/total time 4 slope of line drawn from start to stopping point on a distance time graph.
Average Velocity 4 DISPLACEMENT divided by TIME v avg = average velocity = change in position = displacement change in time time interval