Physicsthe study of the relationship between matter and energy

Motion A change in position in a certain amount of

time

Motion is relative. To know you are moving, you must have a reference point

Distance – how far you traveled

Distance vs. Displacement The distance between the final position and

starting position is displacement (Ex: hiking on a trail. The trail may be 1 mile

long but you may only end up 300 ft from where you started)

Speed Equation Speed – the distance traveled divided by the

time needed to travel that distance SI Unit is meters per second (m/s) Speed = distance

time

D

S T

Practice (Make sure you use the proper units)

If it takes you 3 hours to travel 60 miles, what is your speed??

If you are running 3 miles in 30 minutes, what is your speed?

Constant speed vs. Average speed Constant speed – an object covers equal

distances in equal amounts of time

The speed of moving objects is not always constant

Average speed: total distance

total time

Graphing Speed

What is happening in the following graph?

Velocity Velocity: Speed in a given direction

You can be going the same speed but two different velocities

Velocity = distance + direction

time

D

TV

Acceleration The change in velocity divided by the time

the change occurs

A = Velocity(final) – Velocity(initial)

Time

Acceleration is speeding up, slowing down or changing direction

Stop Here!!!

Warm Up 4/8 Tell me something about Force and Motion

that begins with each letter

R N

S E

T 2 more consonants

L 1 more vowel

Force What causes an object to accelerate?

A force is a push or pull exerted on an object

Force is measured in Newtons (kg m/s2)

In order for an object to speed up, slow down or change direction, a force has to act on that object

Inertia is the object’s tendency to resist changing its motion. The more inertia, the harder it is to start moving or slow it down

Total Force Sometimes, more than one force can act on an object

at the same time. Those forces together will affect the object’s motion.

Forces usually act in pairs with one force acting on either side of the object

The resulting force that exists between two is the total force

Unbalanced Forces

When a total force acts on an object, they are said to be unbalanced.

Unbalanced forces can cause an object to start moving, stop moving, or change direction.

Balanced Forces Balanced forces exist when the total force is

equal to zero.

Balanced forces do not change an object’s motion

Friction and Air Resistance Friction is the force between two objects

in contact that resists motion between two touching surfaces

It is what eventually causes things to slow down and stop

Air Resistance is a form of friction between an object and air molecules

Gravity Gravity is the pull that all matter exerts on other

matter Gravity is dependent on the mass of an object and

the distance between the two objects The greater the mass, the more gravitational pull it will

have (i.e.: earth vs. moon) The greater the distance, the less gravitational pull it will

have Mass vs Weight – weight is the amount of

gravitational pull on a person. So on the moon, your mass would be the same but weight would be different

Free Fall and Terminal Velocity When the only force acting on an object is

gravity, the object is said to be in free fall On earth, this is 9.8 m/s2 - Gravity constant In the absence of air resistance, all objects on

Earth accelerate at the same rate, regardless of their mass.

An object reaches its terminal velocity when the force of gravity is balanced by the force of air resistance

Gravity Demo

Newton’s Laws

Newton’s First Law of Motion “An object at rest will remain at rest and an

object in motion will maintain its velocity unless it experiences an unbalanced force.”

This is often times called the law of Inertia

Newton’s Second Law of Motion “The unbalanced force acting on an object

equals the object’s mass times its acceleration”

F=ma Force is measured in Newtons (kg m/s2)

Newton’s Third Law For every action force, there is an equal and

opposite reaction force

write the following on your notes on force and motion

Forces always act in PAIRS

EX

How much time does it take for a snail to crawl 20 feet if he goes 2 feet/hr

Make sure you have turned in your speed problems worksheet!!!

Get a calculator and begin calculate your speeds for the 4 activities

Remember: Speed = Distance/Time Round everything to the nearest hundreths

(ex. 5.45s) Make sure and list your units in your answers

What is the formula for finding speed?

What is the formula for finding distance?

What is the formula for finding time?

Remember 2nd Law: F=MA

What is speed?How do you calculate it?

Warm Up 11/4Write Q&A Write an example of something that goes

along with each of Newton’s Laws Ex

1st - A car will sit at a stoplight until you press the gas

2nd - It is harder to carry a box of rocks than a box of popcorn

3rd - When birds fly, they push their wings down in order to go up

Warm Up 11/4

List 5 Examples of motion that you see in your everyday activities

Warm Up 11/3 Make a KWL Chart (3 things in each) Tell me what you KNOW about motion What you WANT to know about motion Leave the L blank for now

K LW

Warm Up 11/2Write Q&A

What is Motion? P.102