Physics PresentationFirst to Fourth Grading Lessons

1ST GRADING LESSONS

•Resultant Vector• Speed and Velocity• Projectile Motion

RESULTANT VECTOR

Resultant Vector

Scalars can be added algebraically. However, vectors do not obey the ordinary laws of algebra. This is because vectors possess both magnitude and direction. Vectors are added geometrically. The process of adding two or more vectors is known as addition or composition of vectors. When two or more vectors are added, the result is a single vector called the resultant vector.

1.) Graphical Methoda.) choose a scaleExample:

d1 = 5 km, Ed2 = 2 km, 250 N of E* scale: 1 cm = 1 kmb.) graph the resultant vector

using data

d1

d2

dR

E

S

W

Example ProblemGiven:d1 = 3.5 cm, 32o N of Ed2 = 2.2 cm, 22o W of Nd3 = 2 cm, EdR = ? d1

d2

d3

dR

32o

22o

N

N

E

S

W

a. Measure the given using your ruler. Measure the given angle with your protractor.

b. Follow the direction given and draw the desired distance.c. You can draw an imaginary Cartesian plane to determine directions.d. Connect the points starting from the origin to the end point.

Measure it. This will be the resultant vector.

5.5 cm 45o E of N/ N of E

Resultant Displacement

The displacement of a moving particle is its change of position in a particular direction. To know the displacement of a moving particle, we must know both the length and the direction of the line joining the two positions of the moving particle. Hence, the displacement of a particle or an object involves both magnitude and direction.

Example Problemd1 = 50 kmd2 = 40 km, Ed3 = 30 km, S* scale: 5 mm = 10 kmdR = ?

a. Measure the length with a ruler following your desired scale.b. Connect points starting from the end of the first distance.c. Measure the displacement. It should consist of the distance,

the angles and the direction.

25o

65o

d2

d3

d1

approximately 50 km

dR

23 mm 250 N of E23 mm 65o E of N

2.) Component MethodFind the x and y component

Example: d1 = 2 km, Nd2 = 3 km, Wd3 = 10 km, 30o N of E

d1) dx = 0 dy = 2 km

d2) dx = -3 km dy = 0

Graph:

(+,+)

(-,+)

(-,-) (+,-)

d1

d2

d3

30oa.) Use the graph to determine x and y for each distance. Remember to indicate the sign.

X

Y

d3) x = cos 30o (10) y = sin 30o (10)x = 8.66 y = 5

* Remember that we use cosine for x and sine for y

2.) Component Methodb.) Table

Displacement X Y

d1 0 2

d2 - 3 0

d3 8.66 5

Sd 5.66 7

d = ( Sdx)2 + ( Sdy)2

= ( 5.66 )2 + ( 7 )2 = 9 km

c.) Find the distance using this equationd.) Find the angle using the trigonometric function tan . q

tan q = SdySdx tan = q

7

5.66tan -1

dR = 9 km, 51.04o N of E

SPEED AND VELOCITY

Speed and Velocity

Motion – is a change of position with respect to a frame of reference.

Translatory motion – also known as rectilinear motion; motion along a straight path

Speed – determines how fast an object is moving

Velocity – change in position over time

Please don’t click after this slide. You will be hearing a sound so please maximize the volume of your speakers. Thank you.

Presentation

distance: 80 kmdisplacement: 80 km Ntime: 1 hr

80 km

Formula:S= distance/ timeV= displacement/ time

S = 80 km / 1 hr= 80

km/hr

V = 80 km N / 1 hr= 80 km / hr going N

PROJECTILE MOTION

Projectile Motion 1

Projectile motion refers to the motion of an object projected into the air at an angle. A fewexamples of this include a soccer ball begin kicked, a baseball begin thrown, or an athletelong jumping. Even fireworks and water fountains are examples of projectile motion. In thislesson you will learn the fundamentals of projectile motion.

Projectile & Trajectory

A projectile is any object propelled through space by the exertion of a force which ceases after launch. Although a thrown baseball could be considered a projectile, the word more often refers to a weapon.

A trajectory is the path a moving object follows through space.

Example Problem

Vx = 1 m/s

dy= 1.25 m

dx = ?

t = ?

a.) How long will the ball reach the ground?

Viy = 0 m/s

dy = 1.25 m

t = 2

dy

g

t = 2 ( 1.25

m)

- 9.8

m/s2

= 0.5 s

b.) How far does the ball thrown?

Vx = 1 m/st = o.5 s

dx = Vx(t)

dx = (1 m/s)(0.5 s)

= 0.5 m

2ND GRADING LESSONS

•Angular Acceleration•Expansion Of Liquids•Methods Of Mixture

ANGULAR ACCELERATION

Angular Acceleration

Angular acceleration is the rate of change of angular velocity over time. In SI units, it is measured in radians per second squared (rad/s2), and is usually denoted by the Greek letter alpha (α).

Angular velocity is a vector quantity (more precisely, a pseudo vector) which specifies the angular speed of an object and the axis about which

Rational motions are defined by rational functions (ratio of two polynomial functions) of time. These are called the axis of rotation.

Presentation

q

distance travelledangular displacement/ position

units: degree radians revolution 1 rev. = 360o = 2rad

angular velocity formula:

W = / q t

angular acceleration:

= W / t

= Wf – Wi / t

Linear Motion Relational Motion

Vf = vi + at wf = wi + t

d = vit + at 2

2q = wit + t2

2

d = vf2 – vi2

2aq = wf2 – wi2

2

Example ProblemAn electric motor revolving 2000 rpm slows down uniformly to 1500 rpm in 3 seconds. What is its angular acceleration?

Given: final angular velocity (wf) = 1500 rpminitial angular velocity (wi) = 2000 rpmTime (t) = 3 seconds

= Wf – Wi / t

= (1500 rpm) – (2000 rpm)

3 sec.

= 166.67 rad/ s2

EXPANSION OF LIQUIDS

Thermal Expansion

The expansion in liquid is usually much more than in a solid for a same rise in temperature; on an average 10 times more.

The rate of expansion of a same liquid sometimes differs greatly in different temperature ranges.

Anomalous expansion of water in temperature ranges from oC – 4C.

PresentationV = Vo T

Problem: A Pyrex beaker filled to the brim with 500 cm3 of Hg at oC is heated at 80C. How much Hg will overflow?

change in temp. original

volume constant coefficient

volume

beaker = (9 x 10-6 / C) (500 cm3) (80C) = 0.36 cm3

Vf = vo + V Vf = 500.36 cm3

Hg = (182 x 10-6/ C) (500 cm3) (80C) = (7.28 cm3) vf = 507.28 cm3

7.28 – 0.36 = 6.92 cm3 overflow

METHODS OF MIXTURE

Methods Of Mixture Whenever 2 substances with unequal

temperatures are mixed, heat is transferred from the warmer to the cooler one until both reach the common temp.

The flow of heat is unidirectional. Heat is a form of energy that lost no

energy when transferred.H given off = H absorbed(mass)(specific heat)(change in temp.) given off = (m)(C)(change in temp.) absorbed

Problem100g of iron was heated to 100C and mixed with 22g of H2o at 40C. The final temperature of the mixture was 60C. Show that the heat given off by iron equals the heat absorbed by the water.specific heat for iron = 0.11

cal/ gCspecific heat for water = 1 cal/ g C

m C Tgivenoff

= 100g (0.11 cal / g C) 40C = 440 cal

T = 100C – 60C = 40C

T = 60C – 40C = 20C

m C Tabsorbed

= 22g (1 cal / g C) 20 C = 440 cal

3RD GRADING LESSONS

•Electric Field of Force•Electric Current•Series and Parallel Circuit

ELECTRIC FIELD OF FORCE

Presentation

+q

- q

Unlike signs attract.

+q

+qLike signs

repel.

ProblemA charge of 0.50 MC is placed in an electric filed which intensity is 4.0 x 105 N/C. What is the electrostatic force acting on the charge?

q = 0.50 MC = 5 x 10-7 CIt = 4.0 x 105 N/ C F = IE (q) = (4.0 x 105 N/ C)(5 x 10-7 C)

= 0.2 N

FORMULA:IE = F/ q (wherein F is force and q is charge)IE = kq1q2 = kq1q2 . 1 d2 d2 q qIE = kq d2

ELECTRIC CURRENT

Electric Circuit

An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors, and diodes, connected by conductive wires or traces through which electrical current can flow.

Electric Current

Is a measure of how much charge crosses a portion of a conductor in 1.0 seconds.

Conductors – materials that let electricity flow.

Resistance – opposition offered by any object to the passage of electric current.

OHM’s Law

Ohm’s law states that the current flowing through a current is directly proportional to the potential difference and inversely proportional to the resistance of the circuit.

I = V/ r ; V = IR ; R= V/ I

ProblemA bulb with a resistance of 4.o flows through a current of 15 ampere. What is the bulb’s potential difference?

I = (current) 15 AR = (resistance) 4.0 V = ?

IR = VV = 15A (4.0 ) = 60 voltage

SERIES AND PARALLEL CIRCUIT

Presentation :D

A circuit composed solely of components connected in series is known as a series circuit

Series Circuit

Once the switch is turned on, the bulbs will be lighted.

Both bulbs will not light unless the switch was turned off.

The battery is the source of energy.Both bulbs are connected with the same battery

and the same switch with a single connection.

ProblemYou have 5 appliances connected in series. Refrigerator: R=20 ohms , V = 220 volts, I = 11 amp TV: R = 10 ohms, I = 22 amp Radio: R = 5 ohms, I = 44 amp Iron: R= 75 ohms, I = 3 amp Stove: R = 55 ohms, I = 5 ampa.) what is the total resistance? Rtotal = R1 + R2 + R3 Rtotal = 20 + 10 + 5 + 75 + 55 Rtotal = 165 ohmsb.) what is the total current? I = V / R I = 220 volts 165 ohms I = 1.33 amperec.) the voltage drop of each appliance V = IRV = total current x given resistance

Ref. : (1.33) 20 = 26.6 vTV : (1.33) 10 = 13.3 vRadio : (1.33) 5 = 6.65 vIron : (1.33) 75 = 99.75 vStove: (1.33) 55 = 73.15

estimated 22o volts

Parallel Circuit

A parallel circuit has more than one resistor (anything that uses electricity to do work) and gets its name from having multiple (parallel) paths to move along . Charges can move through any of several paths. If one of the items in the circuit is broken then no charge will move through that path, but other paths will continue to have charges flow through them. Parallel circuits are found in most household electrical wiring. This is done so that lights don't stop working just because you turned your TV off.

Problem

R1 = 2 R3 = 6 R2 = 5 V = 4.5 v

a.) 1/ Rtotal = 1/ R1 + 1/ R2 + 1/ R3 1/ Rtotal = ½ + 1/5 + 1/ 6

= 0.87 Rt = 1 / o.87 = 1.15

b.) It = I1 + I2 + I3 = V/ RI1 = 4.5/ 2 I2 = 4.5/5I3 = 4.5/ 6

= 2.25 + 0.9 + 0.75= 3.9 A

4TH GRADING LESSONS

•Philosophers and Scientists•Reflection and Refraction•Logic Gates

PHILOSOPHERS AND SCIENTISTS

LightPHILOSOPHERS:Plato – the first philosopher to explain the nature of light - light consists of thread like structuresPythagoras – insisted that light travels as tiny particles from a luminous object to the eyeEmpedocles – to him, light travels from the object to the eye in the form of waves

SCIENTISTS:Sir Isaac Newton – light travels in a straight lineChristian Huygens – light is a form of transverse wave motion sent out by luminous bodyThomas Young – light can meet each other and produce bright and dark regions on a screen behindJames Maxwell – light is the result of oscillations of the electrically charged particles of the atom.Max Planck – light is an energy of quanta w/c are transmitted in small quantities from luminous objects Louis Victor de Broglie – light consists of particles and waves

REFLECTION AND REFRACTION

What is Reflection?Reflection is the bouncing of waves when they encounter an obstacle.2 kinds of reflection:a) diffuse reflection – light that hits an object bounces off in

all directionsb) specular reflection – light ray that hits the surface

bounces off in one direction LAW OF

REFLECTIONThe law of reflection states that for a specular surface, the angle of reflection always equals the angle of incidence.

The lines like the normal line, incident ray and reflected ray lies on the same surface.

FACTORS AFFECTING THE AMOUNT OF REFLECTED RAY•Kind of material the object is made of•Smoothness of the surface•Angle at which the light ray strikes the surface

Presentation :D

What is Refraction?Refraction is the bending of light.

If light speeds up as it crosses over, it bends away from the normal line; if it slows down, it bends toward the normal.

The denser the medium, the lesser the light will penetrate. Hence it decreases the speed of light, it bends towards the normal

Towards :D Away :D

Prism Refraction :D

LOGIC GATES

What is a Logic Gate?A gate is a simple electronic circuit or device that performs logical functions. Logic gates are the basic building blocks for a complex digital system.

3 BASIC LOGIC GATES

OR GateAND GateNOT Gate

Truth Table – is a table that shows all possible input combination and the corresponding output combination for a logic gate

George Boole – an English mathematician that proposed the Boolean Algebra symbol

Logic Circuit Symbol – denotes operation

OR Gate

C

A

B

The ‘or’ gate has a symbol like this (Boolean Algebra symbol). The logic circuit symbol for or gate is addition (+). This gate symbolizes the parallel circuit. When one bulb does not work, other bulbs will work because they are not connected by the same wire.

Logic circuit diagramLogic circuit equation: A

+ B = C

A B C

0 0 0

0 1 1

1 0 1

1 1 1

Truth Table

A and B serves as the inputs. When one input is 0 and the other is 1, the output will be 1. When both inputs are zeroes, the output will be zero. When both inputs are ones, the output will be 1.

AND Gate

X

Y

Z

Logic circuit diagramLogic gate equation: X(Y) = ZThe ‘and’ gate has a symbol like this

D (Boolean Algebra symbol). The logic circuit symbol for or gate is multiplication (). This gate symbolizes the series circuit. When one bulb does not work, all the other bulbs connected to it will not work.

Truth Table

X Y Z

0 0 0

0 1 0

1 0 0

1 1 1

X and Y serves as the inputs. When one input is 0 and the other is 1, the output will be 0. When both inputs are zeroes, the output will be zero. When both inputs are ones, the output will be 1.

NOT Gate

I

Logic circuit diagram

Logic gate equation: Ī

The ‘not’ gate has a symbol like this (Boolean Algebra symbol). The symbol ( - ) above the input denotes negation or inversion. This gate symbolizes the inverter.

Truth Table

When In = 0, the base collector function is reverse based. As the emitter current is 0, the base current is also 0 and hence the collector current will be 0. Out is 1. When In = 1, the emitter base function gets forward biased. Out is 0.

In Out

0 1

1 0

ProblemSuppose you are invited in a birthday party by your friend. Before going, you are to consider the following:a.) birthday giftb.) moneyc.) timeIllustrate by using a logic circuit diagram.

gift

money

time

party

We used the or gate for money and gift because you can either bring the gift or give money as a gift to your friend. Together with time that is necessary and must be a factor to consider in the party, you are ready to go!

ExerciseWhat would be their equations?

L

M

N

O

E

F

G

H

(L M) + N = O( E F) ( G) = H

END

PROJECT IN SCIENCE

Patricia Mie V. de Guzman

4th year St. John

Mrs. Hannah B. Yecla

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