Category: KS3 Physics

Light Y7/8 Key Terms

 Term Definition Reflection When light bounces off surfaces. (On a mirror the angle it shines on the mirror and the angle it reflects are the same.) Refraction When light bends when it goes into a different material e.g. glass, water, air. Dispersion When white light separates into colours of the spectrum. Spectrum All the different colours. R, O, Y, G, B, I, V Three primary: green, red, blue. Secondary: green + red = yellow  OR green + blue = cyan OR red + blue = magenta Mirror A shiny surface which reflects light. Triangular Prism This makes light refract inside the prims and disperse in the air into a spectrum of colours Virtual Image Not real – i.e your face that appears inside a mirror behind the wall Vacuum Light does not need a medium to travel through Transparent Light can pass through a transparent sheet of glass Opaque Light cannot travel through a wall Ray diagram A model which uses ruled lines to show the pathway of travel, with arrows, connected up Incident Light going towards a surface Reflected Light going away from a surface (normally as the same angle it came it at) Normal Line at 90 degrees to a surface where you measure the angle from Scattering A rough surface scatters light in all directions so no image is formed Filters Act to filter out all the colours except that one. Translucent Allows some light to pass through but not enough to see detailed shapes Eye Structure Cornea, Pupil, Suspensory ligament, retina, focal point, iris, optic nerve, blind spot EM Spectrum Radio, Micro, IR, ROY-G-BIV, V, X-Ray, Gamma-Ray, (Cosmic) Convex Lens which is fat in the middle and gives a focal point. Common uses are magnifying glasses Concave Lens is skinny in the middle (or like a cave) makes the light spread out or disperse to form virtual images

Y7 Light Resources

Lesson 1 Transmission of Light

Lesson 2 Reflection “Theory”

Lesson 3 Reflection “Practical”

Lesson 4a How We See Colour

Lesson 4b Mixing Colours

Lesson 5 Colour Filters

Y8 Optics and Light Resources…

Lesson 1 Refraction in a Prism

Lesson 2a Dispersion

Lesson 2b Colour

Lesson 3 Lenses

Lesson 4 How We See

Lesson 5 Beyond Light “Hershel’s IR Exp

Interactive Quiz – Waves

Reflection and Refraction

This movie shows refraction, reflection, TIR with prisms.

Sound Resources…

This series of 4 lessons covers Y7 sound and how we hear.

Lesson 1: Vibrations and Waves

Lesson 2: Seeing Sound

Lesson 3: Speed of Sound

Lesson 4 How We Hear

Signal Generator and Oscilloscope

Oscilloscope and Signal Generator showing ideas of frequency and amplitude for Ks3-5 Pupils

Simulation

University of Vienna Simulation (PC version) to look at lenses for the more advanced view) lenses simulation

KS3 Energy Stores and Resources

Resources

Y7 Energy (5 lessons of content)

Types and Stores

Definition

Chemical

Energy stored in a fuel and is obtained by breaking of chemical bonds i.e. burning fuels OR a chemical reaction in a cell/battery

Elastic

Energy stored due to a force on a stretched or compressed spring

Gravitational

Due to the position of an object in a gravitational field height above ground.

Kinetic

Energy stored in a moving object, faster they move the more energy contained

Nuclear

Energy obtained in a splitting the atom (not renewable) gives out a particle radiation

Potential

Energy that is stored in an object ready to be used but not in action. (i.e. chemical, elastic, gravitational potential

Thermal

Energy contained in a objects temperature

Conservation

Energy is never destroyed or made (since the start of the universe) it is only moved around to different places, spread out or concentrated. We say it is “transformed”

Resource

A source where energy can be obtained from i.e. a wind, solar, nuclear, tidal, geothermal, hydroelectric

Renewable

Sources of energy that don’t run out in the lifetime of the planet i.e. solar, wind, geothermal, hydroelectric etc..

Non-Renewable

A fuel that burns OR fuel source that is used up i.e. atoms that splits.

Fuel

A source of energy which can be used up i.e. petrol which is then burned to release the chemical energy

Uranium

a large atom which splits to release thermal/kinetic energy at a power station. It heats water, which turns to steam to turn a turbine and electrical generator.

Mechanism

Energy transfers take place via four mechanisms or carriers: radiation, electrical, mechanical, thermal.

Energy Stores

Energy can be stored in different ways, including:

1. kinetic (in a moving object)
2. chemical (e.g. fuel + oxygen chemical bonds)
3. thermal (in a warm object)
4. nuclear (released through radioactive decay, fission or fusion)
5. gravitational (due to the position of an object in a gravitational field height)
6. magnetic (in two separated magnets that are attracting, or repelling)
7. elastic (e.g. in a stretched or compressed spring)
8. electrostatic (in two separated electric charges that are attracting, or repelling)

Energy Mechanisms / Carriers

Energy can transfer or move from one store to another in different ways. Devices such as lamps and heaters may be involved, or processes such as combustion.

For example, energy can be transferred:

1. mechanically (when a force moves through a distance)
2. electrically (when a charge moves through a potential difference)
3. by heating (because of a temperature difference) thermal difference
4. by radiation (e.g. light, microwaves, sound)

Heating: Some objects are hotter than others. Energy is transferred from the hotter object to the cooler one, and the difference in temperature between them decreases.

Mechanical transfer: Energy can be transferred mechanically through the movement of the parts in machines, and when the motion or position of an object changes. Sound waves and seismic waves (formed during earthquakes) are mechanical waves that transfer energy through materials and from place to place.

Electrical transfer: Energy is transferred when an electrical circuit is complete. A simple circuit may consist of a battery, lamp and wires. Internal energy stored in the battery is transferred to moving charged particles in the wire.

Transfer by radiation: Visible light, infrared light, microwaves and radio waves are forms of radiation. They are carried by waves (although unlike sound, these are not mechanical waves and can travel through empty space). Electric lamps and burning fuels transfer visible and infrared light to the surroundings.

Energy 101: Electricity Generation

Animated correspondent "Little Lee Patrick Sullivan" follows electricity from its source to the light bulb in your home, explaining different fuels, thermal power generation, transmission and the grid.

Space Revision

If you wish to do a bit of revision or learning on KS3, 4 or 5 space. Then try some of the resources here, you can have a PPT or PDF.

Feel free to use for school use, but all images are copyright so no profit or derivatives which you sell!

Chris Hadfield: ‘I’m blind, in space, holding a drill. Houston, I have a problem’

Chris Hadfield: ‘I’m blind, in space, holding a drill. Houston, I have a problem’

https://www.gu.com/p/3jncn

Chris Hadfield: ‘I’m blind, in space, holding a drill. Houston, I have a problem’
An extract from Chris Hadfield’s An Astronaut’s Guide To Life On Earth
Fri 25 October 2013
I am calm the night before my first spacewalk in 2001, but I am also conscious I am about to do something I’ve been dreaming of most of my life. I feel ready – I’ve studied and trained for years. Still, I spend hours polishing the visor of my spacesuit so my breath won’t fog it up, unpacking and checking each piece of gear, pre-assembling as much of it as I can, then carefully attaching it to the wall with Velcro. My crewmate Scott Parazynski and I are installing Canadarm2, the robotic arm that will build the International Space Station, currently still in its infancy. We docked our space shuttle, Endeavour, to it a few days before, but haven’t yet been able to open the hatch because our EVA (extravehicular activity, or spacewalk) is going to take place from the shuttle airlock – essentially a depressurised bridge between the two spacecraft.
There are multiple steps to follow for an EVA; mess one up and you won’t make it out of the spaceship. It will be many busy hours until we can float out of the airlock and Nasa has choreographed them down to five-minute slices, even dictating when and what to eat for breakfast: PowerBars and rehydrated grapefruit juice. I shave, wash up (hair-washing involves scrubbing your scalp vigorously with no-rinse shampoo, then drying off carefully to be sure stray wet hairs don’t wind up floating all over the spacecraft and clogging up air filters or eyes and noses) and use the toilet. (You pick up a thing that looks like a DustBuster with a little yellow funnel attached, then hold it up close so you don’t get pee everywhere. I don’t want to have to use my diaper if I can help it.) Then I pull on the liquid cooling garment, which is like long underwear with a lot of personality; it’s full of clear plastic tubing that water flows through, and we can control the temperature. It feels stiff, like a cheap Halloween costume, but when the sun is shining on you in a spacewalk, the fabric of the spacesuit gets extremely hot and personal air-conditioning seems like a fine idea.
Four hours later, Scott and I are finally floating head to toe in our spacesuits, carefully and slowly depressurising the airlock and checking and rechecking the LED displays on our suits to make sure that they are functioning properly and can keep us alive in the vacuum of space. If there is a leak in the suit out there, our lungs will rupture, our eardrums burst, our saliva, sweat and tears boil, and we’ll get the bends. The only good news is that within 10 to 15 seconds we’ll lose consciousness. Lack of oxygen to the brain is what will finish us off.
When the airlock has finally depressurised, I grab the handle on the hatch and turn it – not easily, because nothing in a spacesuit is easy. The hatch is like a manhole, and it has to be removed and stowed in a bike rack-like contraption overhead. My exit will not be graceful. But my number one concern is to avoid floating off into space, so I’m tethered to Scott and I’m holding another tether to attach to the rail on the side of the shuttle. I lower the gold shield on my visor to protect my eyes from the sun and carefully, gingerly, wriggle my bulky suited self out of the airlock. I’m still inside the belly of the beast, in the payload bay, but my suit has become my own personal spaceship, keeping me alive.
Emerging from the bay, my existence narrows to a single point of focus: attaching my tether to the braided wire strung from one end of the vehicle to the other. I lock on to that and tell everyone I’m securely tethered. Now Scott can come and join me. Waiting for him, I check behind me, to be sure I haven’t accidentally activated my backup tank of oxygen, and that’s when I notice the universe. The scale is graphically shocking. The colours, too. The incongruity is stupefying: there I was, inside a small box, but now – how is this possible? What’s coming out of my mouth is a single word: “Wow.” Only elongated: “Wwwooooowww.” My mind is racing, trying to understand an experience that is so unique. It’s like being engrossed in cleaning a pane of glass, then you look over your shoulder and realise you’re hanging off the Empire State Building, Manhattan sprawled vividly beneath. Of course I’d peered through the shuttle windows at the world, but I understood now that I hadn’t seen it, not really. Holding on to the side of a spaceship that’s moving around the Earth at 17,500 miles an hour, I could truly see the astonishing beauty of our planet, the infinite textures and colours. On the other side of me, the black velvet bucket of space, brimming with stars. It’s vast and overwhelming, this visual immersion, and I could drink it in for ever, only here’s Scott, out of the airlock, floating over towards me. We get to work.
After five hours, the installation is going well, albeit slowly, when I become aware of droplets of water floating around inside my helmet. An EVA is incredibly taxing, physically, and over the years we’ve tried putting some sort of food inside the suit so we have something to eat. But it’s been messy and more hindrance than help, so typically we just have a water bag. You bite on the straw to open a valve, then suck out water – hypothetically, anyway. My water bag hasn’t worked since we started the EVA and now it is apparently leaking.
I’m trying to ignore these little globs of water floating in front of my face when suddenly my left eye starts stinging. It feels as if a large piece of grit has been smashed into it. Instinctively I reach up to rub it – and my hand smacks into my visor. “You’re in a spacesuit, moron!” I remind myself. I blink repeatedly and whip my head from side to side to try to dislodge whatever it is, but my eye won’t stay open for more than a blurry second.
We’ve trained for many eventualities during an EVA, but partial blindness is not one of them. I’m tightening the bolts on Canadarm2 using a big handheld drill. My feet are clicked into the foot restraints and my tether is firmly attached to the space station; I’m at no imminent risk. I decide to keep working and tell no one. I move on to the next bolt, but my left eye is now not only smarting but actually filling with tears.

Hadfield at work in orbit. Photograph: Nasa/Newsmakers/Getty Images
Tears need gravity. On Earth, a little duct above your eye generates tears that flush out any irritant, then overflow down your cheek. In weightlessness tears don’t flow downward. They just sit there and, as you keep on crying, a bigger and bigger ball of salty liquid accumulates to form a wobbly bubble on your eyeball. The growing ball of tears in my left eye oozes over, like a burst dam, invading my right. Within just a few minutes, I’ve gone from 20/20 vision to blind. In space. Holding a drill.
“Houston, EV1. I have a problem.” As the words come out, I can picture the reaction on the ground. First there will be concern for me personally and then, seconds later, everyone at Mission Control will be galvanised, tossing out theories about causes and trying to figure out solutions.
To Scott and me, under-reacting seems the best option: I can’t see, but he’s fine and still working on the wiring on another part of the station. I need to get this job done; the Canadian-designed and built Canadarm2 is both a test and proof of our robotics capability. Crew safety is the number one priority, but we can’t just leave this vital piece of equipment flapping off the side of the space station. The EVA is also a big deal back home: no Canadian has ever walked in space before. In other words, it’s not a good time to be having eye trouble.
The focus on the ground is figuring out what’s causing the contamination. They go straight to the worst-case scenario: maybe the problem is related to the air purification system in the spacewalking suit, which relies on lithium hydroxide to remove carbon dioxide. Lithium hydroxide is caustic and can severely damage your lungs; eye irritation is one of the first signs of a leak. So maybe I’m experiencing early symptoms of exposure and have only a couple more minutes to live. Ellen Ochoa, the Nasa “capcom” who’s the voice of Mission Control, calmly tells me to open my purge valve – essentially, open a hole in my suit.
This goes against my survival instincts, but I start dumping my air into space. I listen to the hissing noise as my oxygen merrily burbles out into the universe. It’s a curiously peaceful moment. Without sight, my body is telling me that nothing out of the ordinary is going on. I feel more like I’m under the covers in bed than hanging on to the side of the station, in mortal danger.
The suit has a significant amount of oxygen, enough for eight or even 10 hours, and I also have a secondary O2 tank, so I can bleed oxygen and stay alive for a long time. But who knows how much longer we’ll have to be outside to finish attaching the arm? I start trying everything I can think of to unblind myself: shaking my head around to brush my eyes against something in the helmet, blinking for all I’m worth. I know the doctors on the ground are undoubtedly saying, “We’ve got to bring him inside right this minute and figure out what’s going on.” So I say, “I feel no lung irritation at all and I think my eyes are starting to clear a little bit.” It’s sort of true. I feel marginally less sightless. I keep blinking and thankfully, 20 minutes on, I think I can see well enough to continue.
Nearing the end (almost three hours later), I look down to watch the world pour by. Having overcome this obstacle and knowing the two of us have accomplished what we set out to do is a big moment. But with a spacewalk, the very last step is as important as the first one, so not until we’ve repressurised the airlock and are actually back inside our spaceship do I let myself relax. As soon as I do, I feel completely drained and just float limply, shivering with cold. My body is out of fuel.
Later, as we’re going over the possibilities of what went wrong, the capcom asks, “Chris, did you remember to use your anti-fog stuff?” Of course I had. The night before I’d polished the visor of the suit. “You didn’t get it all off.” Apparently the solution is basically dishwashing detergent; mix it with a few droplets of loose water and it’s as though you’ve squirted soap directly into your eye. A spacewalk with a multimillion-dollar piece of equipment absolutely vital to the construction of the ISS was jeopardised because of a microscopic drop of cleaning solution.
Eventually, Nasa changed the solution to something less noxious. But in the meantime, thanks to my widely publicised oversight, all astronauts knew to be fanatical about wiping down the interior of their visors. Even in my line of work, it’s the small stuff.
I missed my children in space, but no more than I do on the ground, where I don’t see enough of them either. And I missed my wife. But I wasn’t lonely. Loneliness, I think, has very little to do with location. It’s a state of mind. In the centre of every city are some of the loneliest people in the world. If anything, because our whole planet was just outside the window, I felt even more aware of and connected to the seven billion other people who call it home.

Meteorite pulled from Russian lake

Meteorite pulled from Russian lake https://www.bbc.co.uk/news/science-environment-24550941

Dead star eats water-rich asteroid https://www.bbc.co.uk/news/science-environment-24491845