an introduction to

An Introduction To

FORCE

What is a FORCE?

Any Ideas?

It’s NOT that!

A FORCE is like this…

A FORCE is simplya PUSH or a PULL.

Here are a few examples of a FORCE…

PUSH

PU

LL

PU

SH

PU

LL

PU

LL

PU

SH

PULL

PUSH

PUSH

FORCE is represented using a unit called a NEWTON, which is named after Isaac Newton,

who developed the Laws of Motion.The NEWTON is abbreviated as an “N”.

What is NET FORCE?

NET FORCE is the result of combining all the forces

exerted on an object.

Here, you see all these people pulling this large plane. This is a NET FORCE because there is more than one force being applied to move the plane. PULL WITH ALL YOUR MIGHT!

The cheerleaders on the ground are using their combined forces or NET FORCE to throw the one cheerleader up into the air at a spin.

A Boeing 747, using FOUR jet engines, uses NET FORCE to push its mass into the sky and fly.

A Boeing 747 plane weighs 362,000 pounds!

The parachute has multiple lines connected to the person and is pulling up from different directions. This NET FORCE that is spread

across the parachute is needed to make it work correctly.

Two people are necessary to lift this couch and move it. Without their NET FORCE, the couch would be too heavy!

(Use NET FORCE and… ) JUST KEEP SWIMMING!

http://www.flickclip.com/flicks/findingnemo8.html

With all FORCES… there are balanced and

unbalanced forces.

If FORCES are balanced, then there is NO MOVEMENT.

This monster-truck pull-off isn’t going anywhere!

A magnetic force is pushing the pot up, but the force of gravity is

pulling it down causing it to hover!

A balanced FORCE will have a NET FORCE equal to ZERO.

http://www.youtube.com/watch?v=CMURy4AgZPA

http://www.youtube.com/watch?v=jCM3kkeC4XM

A balanced FORCE: 11 nails on the head of a single nail!

http://www.youtube.com/watch?v=BHWsagl9LDY

An example of the mathematics involved that make a balanced FORCE equal to ZERO is shown below…

Let’s say the person pulling on the LEFT is pulling with 100 Newtons of Force…

100 N 100 N

And the person pulling on the RIGHT is also pulling with 100 Newtons of Force…

Because they are pulling equally in OPPOSITE directions, the two forces cancel each other out. This makes for NO MOTION.

100 N – 100 N = 0 Newtons

Another example of the mathematics involved that make a balanced FORCE equal to ZERO is shown below…

The bison on the LEFT is pushing with 500 Newtons of

Force…

500 N500 N

Because they are pushing equally in OPPOSITE directions, the two forces cancel each other out. This makes for NO MOTION.

500 N – 500 N = 0 Newtons

While the bison on the RIGHT is also pushing with 500 Newtons of Force…

If FORCES are unbalanced,then there IS MOVEMENT.

An unbalanced FORCE will have a NET FORCE greater than ZERO.

An F22 Jet takes off using an incredible amount of force!

Don’t play tug of war against a horse!

http://www.youtube.com/watch?v=-srzT2olJ2Q

http://www.youtube.com/watch?v=CObf-EOTkjI

An example of the mathematics involved that make an unbalanced FORCE greater than ZERO is shown below…

The crane overcomes the force of gravity and makes freight container move by pulling it up.

30100 N – 30000 N = 100 Newtons

The mass multiplied by the gravity of the freight box

gives the it 30000 Newtons of force DOWNWARD.

While the crane pulls with a force of 30100

Newtons UPWARD.

Another example involving an unbalanced FORCE greater than ZERO is shown below…

The force of the kick would definitely overcome the force of gravity sending the soccer ball off hard and fast!

The only force acting on the ball is gravity giving it only about 4.5 Newtons of force DOWNWARD.

While the soccer player kicks with a force of 250 Newtons AT AN ANGLE.

Who do you think will win this battle?

Any Questions?