MOTION!!!

DRY….what does it mean?

DRY

- Dependent variable

- Responding variable

- Graphed on the Y axis

MIX….what does it mean?

MIX

-Manipulated variable

- Independent variable

- Graphed on the X axis

Potential energy - energy at rest An object NOT moving has potential energy.

- energy in motion . A moving object has kinetic energy.

Moving = kineticAt rest and at highest point means it has the most __________ energy.

potential Mostkineticenergy

Kinetic energy

What is motion?

• one object’s distance from another object is changing.

Reference point- a place or objectthat can be used to determine if anobject is in motion.

What causes motion?

Force – A push or a pull

Motion is always caused bya force.

Does every force cause a motion?

Balanced forces –

5 N 5N

does not give us motion.

Unbalanced force –

Unbalanced forces can cause an objectto start moving, stop moving, orchange direction.

5 N 10 N

gives us motion

Unbalanced Forces and Motion

• Head of arrow points in direction of the force• The width tells the strength• Wider the arrow the greater the force• Balanced forces

• Unbalanced forces

100 N25 N

Net force – overall force on an object

125 N

N means Newtons

100 N25 N

75 N

50 N50 N

0 N

40 N 60 N

20 N

An object in motion will eventually stop.

What are some forces thatwill cause an object to stop moving?

Friction• Friction - A force created when two surfaces rub

against each other.

Friction - ice, wood, vinyl

Push a (SEED) book

http://www.seed.slb.com/labcontent.aspx?id=17210

Gravity• Force acts to pull objects straight down toward

the center of Earth• Gravity – force that pulls objects toward

each other.

Weight• Weight – • Mass –.• Which is NOT effected by gravity?

Mass is NOT effected by gravity!

measure of the force of gravity on an object.amount of matter in an object

Air Resistance• All objects are supposed to fall at same rate, not always

the case.• Air resistance – objects falling through air experience

friction from the air which is matter.

Watch and see…...

Free Fall• Free Fall – when the only force acting on a falling object

is gravity.• In free fall; unbalanced force• All objects in free fall accelerate at the same pace

regardless of mass

Archery competition

http://www.seed.slb.com/flash/science/features/people/archery/en/game.htm?width=720&height=500&popup=true

Newton’s First Law of Motion

• First Law of Motion (Law of Inertia) - An object at rest will stay at rest and an object in motion will stay in motion unless acted upon by an unbalanced force.

WEBSITE

Mass and Inertia

• Mass – the amount of matter in an object• Measured with the _____________________

• Volume – the amount of space an object takes up. Measured with the _________________

triple beam balance

graduated cylinder

Newton’s Second Law of Motion

• The greater the mass, the greater the force you need for the same acceleration.

• Force is measured in Newtons

F = mass x acceleration

same

(change in velocity)

Third Law of Motion-

If one object exerts a force on a second object, the second objectexerts a force of equal strengthin the opposite direction.

For every action there is an equal but opposite reaction.

Newton’s Third Law of Motion

• For every action there is an equal and opposite reaction.

• Examples: rockets, swimming, skating, boating.

website

Sir Isaac Newton – English mathematician who proposedthree laws of motion in thelate 1600’s. These laws explain the relationshipamong forces, matter, and motion.

Sir Isaac Newton

His school reports described him as 'idle' and 'inattentive'.

Isaac was taken away from school, but later allowed to return.

Isaac Newton came from a family of farmers

but never knew his father who died in October

1642, three months before his son was born.

The young child was then left in the care of

his grandmother.Basically treated as an orphan,

Isaac did not have a happy childhood.

While Newton was still under 25 years old, he began revolutionary

advances in mathematics, optics, physics, and astronomy

SPEED

Define speed.

Miles per hour

Speed = distance/time

Speed- how far you traveled divided by how long it took you to travel there.

Calculate the speed: A hawk flies 12 km in 2 hours.

Speed= 6 km/hour

Speed = distance/time

We now have speed. So let’s add a direction to that speed. We now havevelocity.

We have two planesleaving Houston BushInternational at 12:05 pm.They both fly at the speedof 140 miles per hour for2 hours. Do they land in the same place?

Velocity is speed with a direction

Usually, a speed of an object is not constant.

25 miles/hour west

Spring scale -

A tool used to measure force.Units are in ____________.Newtons

Force, Mass, and Acceleration

• Acceleration is when an object speeds up, slows down, or changes direction.

Forces- interactive

Newton’s Cradle

DEMO

Balanced Forces are

• A) The overall force on an object.

• B) Unequal forces acting in opposite directions.

• C) Equal forces acting in opposite directions.

Unbalance forces are

• A) The overall force on an object.

• B) Unequal forces acting in opposite directions.

• C) Equal forces acting in opposite directions.

Inertia is

• A) The ability of an object to change its motion

• B) Tendency of an object to resist change in its motion.

• C) The tendency of an object to increase density.

The wider arrow compared to the thinner arrow indicates…

A) A greater force

B) An equal amount of force

C) A smaller force

What is the net force? 25 N 15 N

A. 10 NB. 25 NC. 15 ND. 40 N

Force is measured in

• A) Figs• B) Newtons• C) Grams