Unit 1: Force and motion
Lesson 1: Motion
Position: is the location of an object.
 You can use words (above, below, next to
and far away) to describe position
 When describing position, you must use both distance and direction
Distance: is the amount of space between two objects.
 Units used to measure distance (millimeters,
centimeter, meter and kilometer)
 You can use ruler or meter stick to measure
distance.
Direction: Tells which way a line points from one object
or place to another.
 You can use words (north, south, east, west, left,
right, up, down, forward and backward) to describe
direction
Motion: is the process of changing position.
 Motion can be observed in different
ways (patterns)
 Straight line
 Round (circular)
 Back and forth
 Zigzag pattern
Measuring motion:
To measure motion, you need to know:




Distance
Time
Direction
Speed
Speed: is the measure of how fast or slow something move
Lesson 2: forces can change motion
Force: is a push or a pull
 Force can bs large or small
 It takes larger forces to move heavier objects
Friction force: is a force that occurs when one object rubs against another object
 Friction pushes against moving
objects.
 Friction makes the moving object
slows down.
 Smooth surfaces (as: ice) have
less friction (hard to stop)
 Rough surfaces (as: sand) have
more friction (easily to stop)
Balanced and unbalanced forces
Balanced forces: are forces that cancel each other out when acting together on an object
 Sometimes balanced forces are equal in size
and opposite in direction
 When object is sitting still, all forces acting on it
are balanced
 When objects are moving in constant speed
(‫ ) سرعة ثابتة‬they are also balanced
 Balanced forces don’t cause change in motion
Unbalanced force: forces that are not equal
 If there is more than one force acting on an object, then the total of all forces
determines the direction of motion