Georgia High School Graduation Test

The Science Test

Physics Review

Velocity and Acceleration

Motion- change in position of an object; occurs when a force acts on an object

Speed- rate of change in object’s position

speed= distance/time or V= d/t

Displacement, Velocity & Acceleration

Displacement vs. distance - displacement has a direction

Velocity vs. speed – velocity has a direction

Velocity = displacement timeAcceleration - rate at which velocity

changesAcceleration = final velocity – initial

velocity time

Lesson Review

Time (s) Velocity (m/s)

0 2

1 1.5

2 1

3 0.5

4 0

The table describes the motion of a soccer ball rolling across a field. Think about how the ball’s velocity in meters per second, changes during each second of time. How can you describe the ball’s motion?a. Constant velocityb. Negative accelerationc. Positive accelerationd. Negative velocity

Force

A push or pull

Measured in Newtons

An object at rest and an object moving at a constant velocity is being acted upon by a net force of zero

Force

4 fundamental forcesGravitational F = G X m1xm2

rElectromagnetic - force exerted on

a charged particle in an electromagnetic field

Strong nuclear force – holds the nucleus together by the exchange of mesons

Weak nuclear force – allows for radioactive decay, particularly beta

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Newton’s 1st Law of MotionAn object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an unbalanced force

Law of Inertia—why we wear seat belts.

Momentum

A moving bowling ball has more inertia than a soccer ball moving at the same velocity and is therefore harder to stop.

It has more momentumMomentum depends on its mass and

its velocity

Lesson ReviewWhich of the following is a measure

of an object’s inertia?a. Weight c. volumeb. Mass d. momentumWhat does Newton’s first law of

motion state?c. When one object exerts a force on a second

object, the second object exerts a force in strength, but opposite in direction on the first object

d. The force acting on an object is equal to the mass of the object multiplied by velocity

e. An object at rest remains at rest unless acted upon by an unbalanced force

Newton’s 2nd & 3rd Laws of Motion

F = ma

For every action there is an equal and opposite reaction

Acceleration due to Gravity

On Earth, all objects fall with a constant acceleration of 9.80 m/s2 in the absence of air resistance.

In other words, a falling object’s velocity increases by 9.8 m/s each second it falls!

Mass vs. Weight

Mass—the amount of matter in an object

Weight—the force on a body due to the gravitational attraction of another body

Weight changes based on location.

Mass NEVER changes.

Lesson ReviewTwo 5 kg balls sit on a table. If one of the

balls is replaced with a 10kg ball, what is the effect on the gravitational attraction between the two balls?

a. It is about ¼ of what it was c. it is twice what it was

b. It is about ½ of what it was d. it is four time what it was

Calculate the weight of an object with a mass of 40 kg.

c. 392 Nd. 400 Ne. 492 Nf. 500 N

Work and Power

Work = Force x Distance Measured in Newton-meters or

Joules

Power = Work Time

Measured in Watts

The pitcher does positive work on the ball by transferring energy into it. The pitcher does negative work on it.

Simple machines make work easier

Lever Inclined planeScrewWheel and axleWedgepulley

Lesson ReviewA man is holding a very heavy box

steady in his arms. Which of the following describes the work being done on the box?

a. It is proportional to the force of gravity acting down

b. It is proportional to the weight of the box

c. It is proportional to the force exerted by the man holding the box up

d. It is equal to zero because the box is not moving

Waves

A disturbance that transmits energy through a medium or space

Frequency

The number of events (waves, vibrations, oscillations) that pass a point in a given amount of time, usually a second

High frequency (short wavelength)

Low frequency

(long wave-length)Frequency is related to pitch, the

higher the frequency the higher the pitch

Wave Properties Wavelength - the distance between peak to peak ,

shorter wavelengths = higher frequency Amplitude- the maximum displacement Amplitude is related to intensity, higher the amplitude

the higher the intensity (energy). For sound it means higher volume.

Velocity = frequency x wavelength

Amplitude

Electromagnetic Spectrum

EM waves do not require a medium

Mechanical Waves

Require a mediumSound is an example of a mechanical

waveSound travels best in denser

materials and higher temperaturesEarthquakesOcean waves

Behaviors of Waves

Reflection—wave bounces off barrier

Refraction—wave changes direction as it moves from one medium to another

Diffraction—the bending of a wave around a barrier

Lesson ReviewWhich electromagnetic waves have

the highest energy?a. Gamma rays c. radio wavesb. Infrared waves d. X-raysWhat occurs when light hits a clear

window?c. Most of the light is scatteredd. Most of the light is absorbede. Most of the light is reflectedf. Most of the light is transmitted

To increase the strength of an electromagnet by

a. Increase the number of coilsb. Increase the number of batteries

Electromagnet

Magnetic field

Magnetic field is strongest where the lines are closest together

If you break the magnet, north and south poles will reform on each piece

Electricity

• The movement of electrons in response to a field --- Electricity!

• The electromagnetic force is one of the 4 forces of nature and is described by Coulomb’s Law

Coulomb’s Law

Charged particles exert forces on each other

Like repels, opposites attractThe greater the distance between the

charges the smaller the force

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Static electricity Static electricity is

the charge that stays on an object – does not move

It can be positive or negative

It can be generated by rubbing two objects together and removing “loose” electrons.

Electrical charge generation Induction - charge can be

generated by bringing a touching charged object close to another one

Conduction – charge can be generated by a charged object to another object

Electric CircuitsElectricity is like water flowing

through pipesCharge flows when there is a

difference in potential

Current (I) – flow rate (amperes) Resistance (R) – drag (ohms) Voltage (V) – force or pressure (volts)

Ohm’s Law

V=IR Voltage = Current X Resistance

SI unitsV = volt = 1 joule/1 coulomb I = ampere = 1 coulomb/ secondR = ohm = 1 volt/amp

Series circuit

Series Circuit: the components are lined up along one path. If the circuit is broken, all components turn off.

R = R1 + R2 + R3 + R4

Parallel Circuits

Parallel Circuit – there are several branching paths to the components. If the circuit is broken at any one branch, only the components on that branch will turn off.

1/R = 1/R1 + 1/R2 + 1/R3

Lesson ReviewA grocery store checks the details

of a credit card by having the customer move a magnetic strip on the card past a wire coil. Which principle explains this process?

a. An electrical current produces mechanical energy

b. A permanent magnet produces a changing magnetic field

c. A changing magnetic field produces an electrical current

d. Mechanical energy produces a changing gravitational field

Lesson ReviewLisa has a copper wire, a

permanent magnet, and an iron rod. What can she do with these items to produce an electrical current?

a. Place the wire near the north pole of the permanent magnet

b. Move the permanent magnet rapidly over the wire

c. Touch the ends of the wire to the poles of the magnet

d. Bring the permanent magnet near the end of the iron rod