Review for FinalVocabulary…..

• Gene transfer – moving of a gene from one organism to another• Transgenic animal – animal that has had foreign DNA put into its cells• Cerebrum – part of the brain where thinking takes place• Biotechnology – technology used in agriculture, food science, and medicine• Impulses – a message carried by a neuron• Neurons – the basic functioning units of the nervous system• Cloning – copying a plant or animal• Microinjection – injecting DNA into a cell using a small needle and microscope• Carcinogens – promote the growth of cancer cells• Synapse – the space between neurons• Depressant – drug that slows down the processes of the nervous system• Stimulant – drug that speeds up the activities of the nervous system

More Vocabulary….

The central nervous system is made up of the brain and spinal cordArtificial insemination is when a male’s sperm (semen) is inserted into a female

A force is a push or pull with direction

Displacement vs DistanceDistance – how far something moved (meters)

Displacement – how far, AND what direction something moved (meters to the NW)

Is the red or yellow line distance?Red is distance = how far moved

DISPLACEMENT

DISTANCE

Yellow is displacement = how far and what direction

Displacement is always a straight line, and will always be shorter than distance

Start

Finish

What is a Force?

A force is a push or pull on an object with direction A force has a size AND a directionIs a force a scalar or vector quantity?

Examples of forces: -Pushing your book across a table-Pushing a box

A force must have a direction, so it is a vector quantity

The Units of Force

Force is measured in NewtonsNewton is abbreviated “N”Newton (N) = kg x m/s2

m/s2 is acceleration

So, one Newton is the amount of force that will accelerate a 1 kg object at 1m/s2

Force is mass x acceleration maf

Forces are shown as arrows, or vectors

The longer the arrow (vector), the greater the forceThe direction of the arrow shows you the direction of the force

5 N east

10 N east

Vectors

N

5 N east

10 N east

Adding Forces

More than one force on an object will be added.So, if two people are pushing something east, one pushing with 5N, the other with 10N, what will be the net force on the box?

15 N east = net force

+

Balanced and Unbalances Forces

Balanced forces: when 2 forces cancel each other (no movement)

10 N force east 10 N force west

There is no movement in balanced forces

Example of a balanced force??

NNNf 01010

Balanced and Unbalances Forces

Unbalanced forces: forces that do not cancel (create movement)

10 N force east 15 N force west

Unbalanced forces always create movement

Example of an unbalanced force??

5 N west

NwestNNf 51015 �

Draw a Balanced and Unbalanced force in Your Notebooks

Unbalanced forces (create movement)

10 N force east 15 N force west

5 N west

Balanced forces (do NOT create movement)

Movement to the west

Newton’s First Law (law of inertia)

What is Newton’s 1st law??• Objects in motion stay in motion unless a

force is applied to them• Objects at rest stay at rest unless a force is

applied to them

What is inertia??• Tendency of an object to resist change in its

state of motion

Examples of inertia:-A person flies forward when a car stops-A person flying over bike handlebars

Force is equal to an object’s mass times its acceleration

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Newton’s Second Law

What is the acceleration (a) of the dog sled in the picture?

a = f/ma = 100N/50kga = 2 m/

N = kg x m/s2

N/kg = m/s2

m/s2 = acceleration

Newton’s Third LawAll forces exist in pairsFor every action, there is an equal and opposite reactionTHERE CANNOT BE ONE FORCE

Complete Questions in Notebook1. Using the equation to the right, what will be

more difficult to accelerate, an object with a large or a small mass?

2. Explain Newton’s first, second and third laws and draw a picture to help explain each law.

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ANSWERS1. Using the equation to the right, what will be more difficult to

accelerate, an object with a large or a small mass? a = f/m so it will be easy to accelerate (move) objects with small mass, and hard to accelerate objects with a large mass.2. Explain Newton’s first, second and third laws and draw a

picture to help explain each law. Newton’s first law says that moving objects will keep moving, and that stationary (=not moving) objects will not move. It is sometimes called the law of inertia. Inertia is the tendency of objects to maintain their current state of motion. A man not wearing a seatbelt and flying out of a car is an example of inertia. Newton’s second law states that the force on an object is equal to its mass times its acceleration (f=ma). Newton’s third law says that for every action, there is an equal and opposite reaction. From this, we can deduce that forces must exist in pairs, and that there can never be a single force.

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Review for Final

1. The displacement of a man walking on a curved road is (greater than, less than or equal to) his distance traveled? 2. When you walk across the room the force on your feet is (greater than, less than or equal to) the force on the floor?

Less than

Equal to

Mass vs Weight

Mass is NOT the same as weight!!

Mass – measure of how much matter an object containsWeight – an object’s mass (Kg) times its acceleration (m/s2)

Mass does not change with locationWeight does change with location

Weight is a force and it is a vector quantityMass is a scalar quantity with no direction

Weight is measured in NewtonsMass is measured in Kg

This online weight

calculator told me how much

I weigh on different planets

Does Bart Weigh More on Earth or Jupiter?

Bart weighs more on Jupiter because it’s a larger planet and has a stronger gravitational pull

Is Bart’s Mass Greater on Earth or Jupiter?

Bart’s mass is the same everywhere in the universe. Mass never changes.

50 Kg

50 Kg

What is the difference between mass and weight?

Write answer in your notebooks…

Weight is measured in Newtons and is the product of mass times acceleration. Mass is how much matter an object contains and is measured in kg. The mass of an object will be the same anywhere in the universe, while the weight of an object will change depending on its location. Mass is a scalar quantity, while weight is a vector quantity which means it has direction.

How to calculate acceleration…

A dog speeds up from 0 m/s to 21 m/s in 3 seconds.Calculate the dog’s acceleration in your notebooks

21 m/s – 0 m/s = 21 m/s per 3 seconds21 m/s/3s = 7 m/s/s or 7 m/s2 Is acceleration a vector or scalar quantity?VECTOR!!

Why is it m/s2 and not m/s/s? They are the same thing…

m/s/s = m/s * 1/s = m/s2

m/s/s = m/s2

Notes Online….Go to:www.slideshare.net/TeacherAndrew