Force & Motion

Energy, Force, and Motion identifying energy transformations; Identifying and analyzing the transfer of heat energy by conduction, convection, and radiation interpreting a phase diagram; describing and calculating velocity and acceleration; comparing Newton’s three laws; calculating mechanical advantage; understanding the work of simple machines Waves, Electricity, and Magnetism investigating light and sound phenomena and comparing light to sound; Doppler effect; describing the causes of static electricity; constructing and analyzing series and parallel circuits; describing the relationship between voltage, current and resistance and relating electricity and magnetism and common applications

SPEED Describes how fast an object is moving.

Average Speed distance Average Speed = time

Velocity The speed of an object in a certain direction.

d Velocity V = t V = velocity (meters/second) d = distance (meters) speed of an object in a certain direction. V = velocity (meters/second) d = distance (meters) t = time (seconds)

Velocity speed of an object in a certain direction. seconds 3 1 2

Speed=? Velocity=? Total time= 4 seconds B 20 meters 12 meters

Numerator 5 12 Denominator

Acceleration

Acceleration is how quickly velocity changes over time. X L eh ray shun   Speed 3 1 2 Meters/second

Acceleration (Vfinal - Vinitial) ___________ A = time how quickly velocity changes over time. (Vfinal - Vinitial) ___________ A = time

Acceleration the change in velocity over time.   change in velocity Acceleration = time (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 Vector a measurement that contains direction. Egg sample: Velocity

Gravitational Magnetic Forces of Nature Gravitational 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   An object remains at a in a ,until a net force acts on it. constant speed straight path

An object will remain at a constant speed (unless disturbed). NEWTON’s 1st Law of Motion is the law of Inertia ih ner shah An object will remain at a constant speed (unless disturbed).

the force of a moving body. momentum the force of a moving body. ___________ the mass times velocity of an object p = m • v Momentum = mass x velocity (Kgrams) (meters/second)

p = m • v Momentum = mass x velocity Higher mass higher momentum Higher velocity higher momentum p = m • v

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

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

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

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

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

NEWTON’s 2nd Law of Motion :   An object that has a force acting on it will change its speed (accelerate).

f = m•a NEWTON’s 2nd Law of Motion : f = net force (newtons)   f = m•a force = mass • acceleration f = net force (newtons) m = mass (Kilograms) a = acceleration (meters/second2)

f = m•a NEWTON’s 2nd Law of Motion : mass of the club   f = m•a mass of the club acceleration of the club force of the club

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

When the net force is Zero. -> NO movement Balanced Forces When the net force is Zero. -> NO movement When the net force is NOT Zero. -> movement Unbalanced Forces

When all forces are balanced. The net force is Zero. Static Equilibrium Balanced forces When all forces are balanced. The net force is Zero. There is NO movement. 3 Kg ? 2 Kg

50 N 100 N 50 N 50 N 100 N 50 N

Conservation of energy NEWTON’s 3rd Law of Motion:   Conservation of energy For every action there is an equal and opposite reaction.

NEWTON’s 3rd Law of Motion: For every action, there is   For every action, there is an equal and opposite reaction.

NEWTON’s 3rd Law of Motion: For every action, there is   For every action, there is an equal and opposite reaction.

Balanced or unbalanced? Gravity Inertia Friction Balanced or unbalanced? Action Reaction

Gravity balanced UN BALL Speed (m/s) Ground Time (mSec)

Inertia PUTTER balanced UN Speed (m/s) BALL Time (mSec)

Friction SKATE balanced UN Speed (m/s) Time (Sec)

A car is traveling down a hill 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 deformation generates heat

Friction   the resistive force that occurs when two surfaces contact each other.  

Oliver the dog doesn't want to walk in the rain 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 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 Lab Object Surface force (Newstons)

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

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 the ball with a mass of 25 kg the ball with a mass of 10 kg They all fall at the same rate.

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

Pressure = Force (newtons) Area (m2) 1 Pascal = 1 Newton/meter2

Work

{ Work Distance W = f • d Force { Distance

Gravitational force Gravity

Gravitational force Gravity

Gravitational force INCREASES with Mass 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 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.

50 39.2 29.4 19.6 9.8 Projectile Motion 3 1 2 Velocity (m/s) seconds forward downward 50 39.2 29.4 19.6 9.8 seconds 3 1 2

Projectile Motion Velocity (m/s) forward downward 48 47 46 50 49 39.2 29.4 19.6 9.8 seconds 3 1 2

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 Machines Pulley 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

Lever Wheel/Axle Pulley Wheel & Axle

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 Machines work the same way Force Distance x

Lever action 2 meters 1 meter Force= ? Force=13 N

Mechanical Advantage= final distance starting distance 9 meters 3 meters

Mechanical Advantage= distance distance 8 meters 2 meters

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 Lab A fixed pulley B movable pulley C double pulley (end in top) D double pulley (end in bottom)

Force of the weight ONLY. Pulley Lab DO THIS FIRST! Hook on Bottom dude ! Force of the weight ONLY. 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.

BIG Teeth=16 small Teeth =8 16:8 2:1 Gear Ratio 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 ?              calculating mechanical Advantage M.A. = 800 Kg/200 Kg = 4

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

The inward force on a spinning object, that stops it from going in 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 ul The 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 Panther Productions 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. Panther Productions

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