Voltmeter and Ammeter | Physics

1. When measuring volts it needs to be connected in parallel.
2. When measuring amps it needs to be connected in series.

Circuits

Voltage:

Voltage is the force from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop, allowing them to do work such as light. 

Voltmeter:

Voltage is the number of electrons in a circuit. It is measured with a voltmeter. 

Current:

Is the number of electrons passing in a given point in one second.

Circuits | Physics

Activity: 

Go on to the PHET website and click on LAB: https://phet.colorado.edu/sims/html/circuit-construction-kit-dc/latest/circuit-construction-kit-dc_en.html

I want you to construct a few different circuits, try to make them and then take a screenshot of them and post the pic here.

1. A circuit containing a battery, a light bulb, connected by wires:

2. Now add a switch into the circuit you just made, what happens when the switch is open or closed?

3. Now click on the battery and increase the voltage it supplies to the circuit. What happened?

4. Underneath the switch there is an arrow, scroll through the options to the end and try putting some random things into the circuit like a coin or dog. What happens to light bulbs?

Circuit | Physics

Definition:

Cell

Supplies energy to circuit, by pushing current from the positive to negative end

Voltmeter

A device used to measure voltage, or electrical potential energy difference

Ammeter

A device used to measure current in a circuit

Wire

a thin, flexible thread of metal

Resistor

An electrical device that resists the flow of electrical current

Bulb

In a circuit, this shows if electricity is flowing by lighting up

Switch

a device that opens or closes a circuit

Battery

A device that converts chemical energy to electrical energy

Activity: 

Go on to the PHET website and click on LAB: https://phet.colorado.edu/sims/html/circuit-construction-kit-dc/latest/circuit-construction-kit-dc_en.html

I want you to construct a few different circuits, try to make them and then take a screenshot of them and post the pic here.

1. A circuit containing a battery, a light bulb, connected by wires:

2. Now add a switch into the circuit you just made, what happens when the switch is open or closed?

Electricity Circuits

There are two forms of circuits; Series and Parallel. 

Houses have Parallel circuits are found in houses. If one bulb blows out, then the rest of them are on.

Series Circuit
Credit: https://sites.google.com/site/lamsnc2dvella/Home/grade-9e-science/unit-3---electricity/series-and-parallel-circuit

Parallel Circuit
Credit: https://www.allaboutcircuits.com/textbook/direct-current/chpt-5/what-are-series-and-parallel-circuits/

Parallel

A circuit in which the bulbs are divided up evenly.

Series

A circuit in which the bulbs are in one continuous line.

Electricity | Physics

Van de Graaff generator generates static electricity.

We first looked at this video of static electricity by TedEd. 

Static Electricity

A build up of electrical charges on an object

Current Electricity

A flow of electric charge.

Electrical Charge

Electrical particles that are negatively charged

Circuit

A system that provides a pathway for electrical current to flow through

Cell

Supplies energy to circuit, by pushing current from the positive to negative end

Voltmeter

A device used to measure voltage, or electrical potential energy difference

Activity:

1 - Fill in the table

	Static electricity	Current electricity
What is it caused by?	When there is an imbalance between negative and positive charges within or on the surface of a material.	It can be generated when a moving metal wire through a magnetic field.
Do the negative charges move?	Yes	No
Does it power appliances?	No	Yes

Van De Graaff generator

2 - What are some examples of static electricity:

• Carpet

• Lightning

• Trampoline

• Hair

Write up for a Van der Graaff experiment:

How does the Van der Graaff machine work?

The Van der Graaff machine pulls electrons, moves them along a belt and stores them on the large sphere. These electrons repel each other and try to get as far away from each other as possible, spreading out on the surface of the sphere.

What was one of the experiments they did with the machine?

Putting your hand on the Van der Graaff machine and waiting for your hair to stick up. 

Describe what happened, what did you see?

After some time, the hair sticked up which looked cool. But, when the machine stopped then the hair goes back to normal.

Why did you see this happen?

The Eye - Conclusion

The Eye

Section 1: Label the diagram of the eye.

1. Sclera
2. lens
3. Iris
4. Cornea
5. Retina
6. Pupil
7. Optic Nerve

Quizlet: The Eye

Section 2: Complete the optical illusions and write down how you think each optical illusion works.

Optical Illusions

1. Young

2. Yes

3. Neither, both are the same size

4. Two faces and then see a white vase

5. Small is bigger

6. See three blocks of rectangle prism.

7. Can see white arrows going up and down and lines of black as well

8. A line with various arrows

9. A staircase

10. Blocks of rectangles

11. Two blocks

12. Various optical illusion triangle

13. One circle with another line dotted around and another circle where the dotted line is inside

14. Many shapes

Section 3: Find 10 interesting facts about the eye.

1. Your eye focuses on 50 different objects every second.   

2. Your eyes can see approximately 10 million different colours.

3. It is impossible to sneeze with your eyes open.

4. 80% of all learning comes through your eyes.

5. An average person blinks 12 times a minute.

6. The optic nerve contains more than one million nerve cells.

7. On average, you will blink approximately 4,200,000 times in a single year.

8. 80% of our memories are determined by what we see.

9. A blink typically lasts 100-150 milliseconds.

10. If the human eye was a digital camera, it would have 576 megapixels.

Interesting Facts

Section 4: Colour Blindness Eye test

Eye Test 

1. What are your colour blind test results?

2. Inconclusive

3. What does this mean?

4. Fine

5. What is normal colour vision?

6. It uses all three types of light cones correctly and is known as trichromacy.

Eye Dissection | Physics

Aim: To Dissect a cows eye and look at the different parts of the eye.

Equipment:

1. A cows eye
2. Scissors
3. Tweezers
4. Rubber Gloves

Before Dissection

Method:

1. Set up a treat with newspaper on the desk, the tray on top and the scissors and tweezers in the tray.
2. Put on a rubber glove.
3. Start to remove the excess fat and meat from around the eyeball before dissecting it.
4. Puncture a hole in the cornea where the cornea and the sclera meet.
5. Cut around the cornea so that the vitreous fluid leaks out of the eye onto the tray.
6. Once the cornea has been totally removed you will be able to remove the lens from the iris.
7. Cut the eye un half so that the inside is totally exposed. Once this has been done you will be able to access the retina at the back of the eye.
8. You should now have placed the retina, lens, cornea and iris on a piece of paper.
9. The dissection is not completed and all the parts of the eye need to be wrapped up and trashed. The trays and utensils that were needed must be rinsed and the rubber gloves thrown out.

Summary:

The cow's eye has exactly the same parts as the human eye except for its ability to see better in the dark.

After Dissection

The Eye | Physics

Yesterday, we looked at the eye and writing the purpose of that part of the eye. 

Part of eye	Purpose
Retina	The retina is located at the back of the eye, and when light hits the retina, it activates two types of cells, rods and cones. Rods identify light and dark and support images under dark and dim conditions. Cones are responsible for colour vision - red, green and blue, which detects a range of wavelengths, not the three specific colours.
Pupil	The size of the pupil determined by the iris, as the pupil gets bigger, as more light enters the eye.
Cornea	Light goes through the cornea, the transparent outer covering of the eye. Because the eyeball is round, the cornea acts as a lens, it bends or refracts light.
Optic Nerve	Where it sends light to the brain.
Iris	Light travels through the cornea and aqueous humour (helps to shape the cornea and provides nourishment to the eye.
Lens	Allows the eye to focus on either near and distant objects.
Vitreous humour	Is a clear watery gel that helps the eye and allows for this distance.

Curved Mirrors | Physics

There are three main types of mirrors in the laboratory. Plane mirrors are flat, convex and concave mirrors are both curved mirrors.

Types of Spherical Mirrors | BYJU'S
Credit: https://byjus.com/physics/concave-and-convex-mirrors-spherical-mirrors/

Concave mirrors have the shiny surface on the inside of the curve. When looking at a tablespoon, the bowl of the spoon is concave.

Convex mirrors have the shiny surface on the outside of the curve. When looking at a tablespoon, the back of the spoon is convex.

Observing Reflection in Curved Mirrors

Aim: To investigate the reflection of light rays in concave and convex mirrors.

Equipment:

• Ray box
• Triple-set ray slide
• Concave and convex mirrors
• Power supply

Method:

1. Set up your ray box, triple-set ray slide and power supply.
2. Place the mirrors as indicated on the images below. Place the ray box at the top of the page and shine the 3 rays of light at the mirror.
3. Ensure that the middle ray of light is hitting the mirror at a 90° angle.
4. Carefully trace the direction of the three incident rays and the three reflected rays.

Concave Mirror

Convex Mirror

Reflection and Refraction | Physics

Definition

Reflection

The bouncing back of a wave when it hits a surface through which it cannot pass.

Refraction

The bending of a wave as it passes at an angle from one medium to another

Incident ray

Incoming ray

Reflected Ray

the light ray that bounces off a surface

Refracted Ray

The Ray that has bent as it enters a new medium

Normal line

imaginary line drawn perpendicular to the surface of a mirror or any surface

Angle

The amount of bending that a light ray experiences

Complete the sentences using the following keywords:

Reflection light  reflected  normal same incidence

When light hits a mirror, the angle at which it hits is the incidence as the angle at which it is reflected. Scientists called this the Law of Reflection. In correct science terms, the Reflection Law states that the angle of normal is equal to the angle of same when measured from the reflection. 

Diagram

Research Task

What is a periscope?

Is an instrument to see over, around or through an object which is above the level of direct sight. A periscope consists mainly of a tube with an arrangement of prisms or mirrors, and usually, lenses - used especially in submarines. 

How does it work?

Mirrors are placed at a 45° angle because light always reflects away from a mirror at the same angle that it hits it. There are usually two mirrors in a periscope. 

Simple Periscope

Draw and label a periscope?

Refraction Through Lenses | Physics

One of the most important uses of reflection involves lenses. By controlling how much, and in what direction, light bends we are able to see, heat objects and send information. A lens is simply a refracting object with a curved surface. The two main types of lenses are convex and concave. 

Investigating Refraction Through Lenses

Aim: To investigate how different types of lenses refract light.

Equipment:

• Triple-split ray slide
• Power supply
• Concave lens
• Convex lens

Method:

1. Set up a ray box, triple-slit ray slide and power supply.
2. Place the convex lens and place the ray box near the convex lens, and shine the three rays of light at the lens. Make sure the central light hits the lens at 90° as indicated in the diagram.
3. Carefully trace the direction of the incoming ray and refracted rays.
4. Repeat using the concave lens.

Results:

Convex Lens

Convex Lens

Concave Lens

Concave Lens

Conclusion:

The following sentences describe the way light refracts through the two different lenses. Read the sentences and identify which lens relates to each sentence.

When light passes through this type of lens, the rays all move away (diverge) from each other. One use of these lenses is in security peepholes in a door so that a person inside a room can see who is at the door without having to open it.

1.        The lenses described in the paragraph above is a concave. 

When light passes through this type of lens, the rays all move towards (converge) each other. One use of these lenses is in a camera, to focus the light onto the film or digital sensor. Magnifying glasses also use this type of lenses.

2. The lens described in the paragraph above is a convex.

Speed of Light | Physics

Speed of Light - 300,000,000 m/s

From Cape Reinga to Bluff - 0.006 seconds 

Formula

Time Taken = Distance/Speed of Light

Bouncing Light

Aim: To investigate how light behaves when it hits a plane (flat) mirror. 

Equipment:

1. Lightbox
2. Power Supply
3. Mirror

Method:

1. Collect a ray box power supply and single-slit ray slide from your teacher, and set them up to produce a single beam of light.
2. Place a plane mirror on the diagram of the protractor.
3. Vary the angle of incidence and record the angle of reflection.

Results:

Angle of Incidence	Angle of Reflection
0°	0°
10°	20°
20°	30°
30°	40°
40°	50°
50°	60°
60°	70°
70°	70°
80°	80°

1. Complete the following sentences using the word list below.

      reflection        light        reflected        normal        same        incidence

When light hits a mirror, the angle in which it hits the _____________ as the angle at which it is _________. Scientists called this the Refletion Law. In correct scientific terms, the Reflection Law states that the angle of ________ is equal to the angle of  __________ when measures from _______.