How do objects move?
Motion
- It is the change in the position (Location)
Types of motion
Up and down
motion
Ex. See saw
Straight line
motion
Round and
round motion
Ex. Merry go
round
Zigzag
motion
Back and forth
motion
Ex. Swing
How can we measure motion?
- Motion can be fast or low.
Distance
-It is how far an object is from one position to
another.
- Measured by: Ruler & Measuring tape
- Units: Cm, meters & kilometers.
Time
- Units: seconds, minutes , hours, days, years.
Speed
-It is the distance an object moves in a certain time.
Speed = Distance/Time
Force
Any type of push & pull
Things that affect motion of an object
1- The strength of the force:
Toss ball gently
it will be near
Toss ball hard
it will be far
2- The direction of the force:
- Pushing the table to the right.
- Pulling the drawer out.
- Pushing the stroller to the left.
3- The mass of the object:
- It is the amount of material in an object.
Small mass
is easy to move
Big mass
is harder to move
{It is easier to push an empty shopping cart
than to push a full one}
Friction
- It is the kind of force that stops or slows things
down.
{It prevents us from slipping or falling down}
- It is caused when two objects rub together.
Examples
1) Friction between the tires of a car & the
road.
2) Friction between the bottom of your
sneakers & the ground.
3) Friction between the brakes of the bicycle &
the bicycle wheels.
4) Friction between the train
Wheels & rails
Increasing / Decreasing friction
• Ice & water make surfaces slippery, this
decrease the friction.
{This why skaters can slide easily & smoothly}
• Tires of cars have rough surfaces to increase
the friction between the road & the car
preventing cars from slipping on an inclined
plane.
• Lubricating “putting oil” to bicycles decrease
friction & makes bicycles move faster.
• Lubricating doors decrease friction making
doors easy to open & close
Gravity
• It is the force that pull objects down towards
the earth.
• As the mass of the object becomes larger, the
force of gravity becomes stronger.
Weight
Weight = Mass + Gravity
{Objects with large mass weigh more}