1. Forces & Megastructures
In creating the greatest megastructures on earth, forces are the one of the most important scientific components which impact on construction and development...

2. Forces in Action Why doesn’t gravity make you fall through the floor?
Why do some athletes shave their necks, head and arms?
How fast do skydivers fall through the air?
How does a seatbelt protect you in a car accident?

3. What is a Force?
A force is something that makes something or someone move.
- A force is a PUSH, PULL or a TWIST.
- Force is measured in units called Newtons (N).

4. Push Click on the 2 pictures that show something being pushed. twist
pull
pull

5. Pull Click on the 2 pictures that show something being pulled. twist
push

6. Twist Click on the 2 pictures that show something being twisted. pull
push
push

7. Balanced Forces
If two equal forces are applied to an object in opposite directions, the object does not move / or moves as a constant speed. This is called balanced forces.
ARM WRESTLERS...

8. Unbalanced forces
If two unequal forces are applied to an object in opposite directions, the object does move. This is called unbalanced forces.

9. Unbalanced Forces
If the forces acting on an object are not balanced then the object with either:
Speed up
Slow down
Change direction
Change its shape

10. Example…
When a tennis ball hits a racket, it is obvious that a force is acting on the ball...
There is also a force acting on the racket as well...

11. Forces can start motion
Forces can stop motion
Speed up motion
Change the direction of motion
Have no effect at all
Changes the shape of objects
Slow down motion

12. Types of Force CONTACT FORCE
Friction: A force that acts against the movement of an object. It occurs between any surfaces that are touching and trying to move past each other.
Buoyancy: An upward acting force exerted by liquid, that opposes an object’s weight.
NON-CONTACT FORCE
Gravity: The force of attraction that exists between any two bodies in the universe that have mass. Gravity pulls objects to the centre of the Earth.
Magnetics: An invisible force that either attracts or repels magnetic objects eg. Metals.
Electrostatics: An invisible force that is generated by electrostatic energy.

13. Examples in everyday life
Complete the following…
Effect
Examples in everyday life
Starting a motion
Stopping a motion
Speeding up a motion
Slowing down a motion
Changing the direction of motion
Changing the shape of an object
Having to visible effects

14. Force can be divided into
The following…
Gravity
Magnetics
Air resistance
Friction
Newton’s Laws of Motion