Mechanics

MOTION defined as the movement of an object

exhibited by a change in position

Motion or Movement is a Change In Position

10 ft.

Position A

Position B

DISTANCE AND DISPLACEMENT

1.DISTANCE - the total path length traversed by an object moving from one location to another

- a scalar quantity which has only magnitude.

2. DISPLACEMENT- refers to the straight line distance between the starting and end points.

- a vector quantity which has both magnitude and direction

Distance and Displacement

START

FINISH

Need to distinguish how long we traveled from how far away (and in what direction) we traveled.

your home

your school

A displacement has

Size = length of this arrow

displacement from home to school

displacement from home to school

2 Displacement and distanceTo go to school from home...

size & direction.

Distance = length of path you travelled

( size of displacement)

l1l2l3

2 Displacement and distanceTo go to school from home... your

home

your school = l1 + l2 + l3

SPEED AND VELOCITY:

• SPEED- a scalar quantity which measures how fast something is moving.

Speed equation = distance / timeV = d / tUnit is m/s or Km/h

SPEED-the rate at which distance is covered at a given time

average speed- defined as the total distance traveled divided by the time it took to travel the distance.

the speed of a body at any instant.

Instantaneous speed

•VELOCITY- a vector quantity that represents a rate of change of displacement.

Justin walks 5 km/hr. How long did it take him to travel 15 km?