Force Motion

Energy, Force, and Motion identifying energy transformations; Identifying and analyzing the transfer of heat energy by conduction, convection, and radiationinterpreting a phase diagram; describing and calculating velocity and acceleration;comparing Newton’s three laws; calculating mechanical advantage; understandingthe work of simple machines

Waves, Electricity, and Magnetisminvestigating light and sound phenomena and comparing light to sound; Doppler effect; describing the causes of static electricity; constructing and analyzingseries and parallel circuits; describing the relationship between voltage, current andresistance and relating electricity and magnetism and common applications

SPEED

Describes how fast an object is moving.

Average Speed =distancetime

Velocity The speed of an object in a certain direction.

Velocity

V = velocity (meters/second)d = distance (meters)t = time (seconds)

d V = tspeed of an object in a certain direction.

Velocityspeed of an object in a certain direction.

seconds

0

2

13

Speed=? Velocity=?

16 meters

12 meters

20 meters

Total time=4 seconds

Numerator

Denominator

512

Acceleration

Acceleration is how quickly velocity changes over time.X L eh ray shun

Speed

0

2

13

Meters/second

Accelerationhow quickly velocity changes over time.

A = (Vfinal - Vinitial) time

___________

Acceleration the change in velocity over time.

Acceleration = change in velocitytime

(v2 – v1 )Acceleration =Time

________

V1 = beginning velocity V2 = ending velocity

The graph below relates speed and time of four cars (1, 2, 3, and 4) traveling along a straight highway.

Which two cars move with zero acceleration?

1 and 4

2 and 3

1 and 2

3 and 4

Which of the following is certain to change as a ball accelerates?

mass of the ball

inertia of the ball

velocity of the ball

force acting on the ball

What must happen to an object in order to accelerate it?

A net force must be applied.

Some weight must be removed.

Its frictional coefficient must be reduced.

It must contain momentum.

Which of these describes the object with the largest

acceleration ?

An object with a small change in velocity over a small change in time

An object with a small change in velocity over a large change in time

An object with a large change in velocity over a small change in time

An object with a large change in velocity over a large change in time

Scalar a measurement that does NOT contain direction. Egg sample: Speed

Vectora measurement that contains

direction.Egg sample: Velocity

Forces of NatureGravitational Magnetic

Mass and Inertia

The universe consists of matter in motion

The greater the mass the harder it is to move. And . . .the harder it is to stop moving.

Lower mass objects are easier to move . . .and to stop moving.

NEWTON’s Laws 1st Law of Motion :

An object remains at a

in a ,until a net force acts on it.

constant speed straight path

ih ner shahAn object willremain at a

constant speed (unless

disturbed).

NEWTON’s 1st Law of Motion is the law of

the mass times velocity of an objectp = m • v

Momentum = mass x velocity (Kgrams) (meters/second)

the force of a moving body.

Higher mass higher momentumHigher velocity higher momentum

Momentum = mass x velocity

p = m • v

includes velocity. So, it has direction. Momentum points in the direction of motion.

Conservation of momentumWhen objects collide, all of the momentum goes somewhere.




NEWTON’s2nd Law of Motion : An object that

has a force acting on it will change its speed (accelerate).

NEWTON’s2nd Law of Motion : f = m•a

f = net force (newtons)m = mass (Kilograms)a = acceleration (meters/second2)

force = mass • acceleration

NEWTON’s2nd Law of Motion :

f = m•aacceleration of the club

force of the club

mass of the club

Net force is the total amount of Force (minus the forces that cancel each other out). Force of gravity

Force of musclesNet force

When the net force is Zero.-> NO movement

When the net force is NOT Zero.-> movement

2 Kg ?

Static Equilibrium Balanced forces When all forces are balanced. The net force is Zero. There is NO movement.

3 Kg

50 N100 N

100 N

50 N

50 N

50 N

NEWTON’s 3rd Law of Motion:

For every action there is an equal and opposite reaction.


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


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

Balanced or unbalanced?Action

Reaction

Gravity Inertia Friction

Gravity balancedUN

Time (mSec)Sp

eed

(m/s

) BALL

Ground

Inertia balancedUN

Time (mSec)Sp

eed

(m/s

)BALL

PUTTER

Friction balancedUN

Time (Sec)Sp

eed

(m/s

)

SKATE

A car is traveling down a hill. Which of the following will affect the amount of energy the car has?

how long the car is

the time of day

how much the car weighs

the color of the car

Friction the resistive force that occurs

when two surfaces travel past each other.

causes physical deformationgenerates heat

Friction the resistive

force that occurs when two surfaces contact each other.

Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to

get him out the door by

sitting on the vinyl floor. sitting on the tile floor.

sitting on the carpeted floor. sitting on the wood floor.

Pauline needs to measure the sliding friction of a brick. How should she go about doing this?

attach the brick to a string and then to a spring scale and read the force needed to quickly lift the brick off the ground

drag the brick by a string attached to a spring scale so that it gradually speeds up

drag the brick by a string attached to a spring scale along the surface of a table at a constant speed and read the force

hang the brick from a string attached to a spring scale and read the force

Sliding friction-the drag force created when the surface of one object slides across the surface of another object.

Sliding Friction LabObjectSurfaceforce (Newstons)

terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster.

In the absence of air resistance, which of these objects will fall at the fastest rate when dropped?

the ball with a mass of 75 kg



They all fall at the same rate.

Pressure is the amount of force exerted over a certain area.

Pressure = ForceArea

Pressure = Force (newtons) Area (m2)

1 Pascal = 1 Newton/meter2

W = f • d

{Distance

Force

{Distance

Gravitational force

Gravitational force

Gravitational forceo INCREASES with Masso DECREASES with Distance

All objects in the universe are attracted to each other by the force of

effort.

friction.

gravity.

inertia.

Four pairs of objects have the masses shown below. If the objects in each pair are the same distance apart, the gravitational force between the objects in which pair is greatest?

1 kilogram and 1 kilogram

1 kilogram and 2 kilograms

2 kilograms and 1 kilogram

2 kilograms and 2 kilograms

As an astronaut travels from Earth to a space station orbiting Earth, what happens to her mass and weight?

Her mass decreases, but her weight remains the same.

Her mass increases as her weight decreases.

Her mass remains the same, but her weight decreases.

Her mass decreases and her weight also decreases.

Which hill would you slide down the fastest?

hill A

hill B

hill C

It would take the same time to slide down all of the hills.

Projectile Motion

seconds

0

2

13

Velocity (m/s)forward downward

050 9.819.629.439.2

Projectile Motion

seconds

0

2

13

Velocity (m/s)forward downward

050 9.819.629.439.249 48 47 46

Simple Machines and work

Lever Inclined plane Pulley Wedge Screw Wheel and axle

Simple Machines• Pulley• Wheel &

Axle• Lever• Inclined plane• Screw• Wedge• Gear

Simple MachinesPulley

Wheel & Axle

Lever

Inclined plane

Screw

Wedge

Gear

Which activity involves the use of a simple machine?

riding on a seesaw

flying a kite

listening to a radio

skiing down a hill

Simple Machine

A mechanism that lowers the amount of force needed to do work, by increasing

the distance.

On which simple machine is a fulcrum found?

pulley

wheel

axle

lever

ALL Simple Machineswork the same way

1 meter2 meters

Lever action

Force=13 N Force= ?

3 meters9 meters

Mechanical Advantage= final distance starting distance

2 meters8 meters

Mechanical Advantage= distance distance

Which of the following is often used as a lever?

file

nail

saw

crowbar

The Wedge

The bottom of this light bulb is an example of what type of simple machine?

a lever

a pulley

a screw

a wedge

What type of simple machine is used to split things apart?

screw

wheel and axle

wedge

inclined plane

What type of simple machine is used to pull a flag up to the top of a flagpole?

screw

wheel and axle

inclined plane

pulley

Pulley LabA fixed pulleyB movable pulleyC double pulley (end in top)D double pulley (end in bottom)

A. fixed pulley B. movable pulley

C. double pulley (end in top) D. double pulley (end in bottom)

Get out your own sheet of paper

1. Write down the force of the weight (newtons).

2. For each pulley system write down the NEW force of the weight.

• Pull the string exactly 20 cm.

• Write down the distance (cm) that the weight moved.

• Calculate the mechanical advantage.

Force of the weight ONLY.

Hook onBottomdude !

DO THIS FIRST!

BIG Teeth=16small Teeth =8

16:82:1

So, the small gear spins TWICE AS FAST

as the big gear.

calculating mechanical Advantage

A 200 pound man lifts a rock weighing 800 pounds by standing on the end of a lever. How much mechanical advantage did the lever provide ? M.A. = 800 Kg/200 Kg = 4

If you wuz ‘n aMerry-go-round & yuz let go,Which wayz wud yu go?

Centripetal force The inward force on a spinning object,that stops it from going in a straight line.

Perpendicular

Centripetal force

Centripetal force sen tripit ulThe inward force on a Spinning object.

Centripetal force The inward force on a Spinning object.

Satellites stay in place as they orbit because of . . .

the repeated firing of rocket boosters.

the gravitational pull of Earth.

a narrow path through the vacuum of space.

solar panels generating energy to hold them in place

The End

Produced by Jake Israel

Directed by Jake Israel

Original Story by Jake Israel

Screenplay Jake Israel

Engineer Jake Israel

Photo enhancement Jake Israel

Casting Jake Israel

Editor Jake Israel

Custom animation Jake Israel

Location manager Jake Israel

Special Effects Jake Israel

Field research Jake Israel

© 2009 All rights reserved.

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Force Motion