Flashcards
Physics
Flashcards do conjunto (37)
- 1Force (3):-Push
-Pull
-Twist - 2Changes (3):-Shape
-Speed
-Direction - 3Friction (7)- Opposes motion
- Stops things starting to move (static friction).
- Slows things down + heats things up (dynamic friction).
- Changes movement energy into heat energy.
- Caused by the roughness of a surface.
-Lubricating (putting on oil) reduces friction.
- Air resistance and water resistance are forms of friction. - 4Air Resistance (2)-Friction caused by moving through air.
- Greater speed. Greater air resistance. - 5Water Resistance (2)-Friction caused by moving through water.
- Greater speed. Greater water resistance. - 6Upthrust (1)If something floats, the upthrust= the weight.
- 7Thrust (1)The forwards force given by moving/ driving forwards.
- 8Normal Reaction Force (2)- The force that keeps something from falling through another thing.
- If the object is still, it is equal to the weight. - 9Arrows (7)-Can be used to represent forces.
- Should be drawn in proportion to the size of the force.
- Point in the right direction of the force.
- Can be added up backwards+ forwards/ up+ down.
- Backwards+ forwards are independant from up+ down.
- Balanced= no force acting.
- Resultant force: the force left after adding up the arrows. CAUSES OBJECT TO CHANGE SHAPE, SPEED OR DIRECTION. - 10Mass (3)- What on object is made out of.
- CANNOT change unless different mass is added.
- The amount of gravity is due to an objects mass. - 11Weight (2)- A force that pulls objects to the centre of any mass.
- Weight= mass x gravity - 12Floating, Sinking + Density (6)- If something is heavy, it has a large mass.
- Density= how much mass fits into a space.
- Density= mass divided by volume
- The forces acting on an object in a liquid is weight (pushing down) and upthrust (pushing up).
- If the density of the object is greater than the density of the water, it sinks.
- If the density of the object is less than the density of the water, it floats. - 13Springs (5)- Extended when a force is applied.
- When not moving, they pull or push with SPRING FORCE or TENSION.
- Tension must equal force (usually weight) for forces to be balanced.
- Elastic: they return to their original length until stretched beyond a certain limit (THE ELASTIC LIMIT). They become plastic.
- The extension increases when a force is applied. This makes them useful for measuring forces. - 14Stopping Distance (7, 5, 3)- The distance it takes a car to stop when driving.
- How long it takes the driver to think how long it takes to break.
- Stopping Distance= Thinking Distance + Breaking Distance.
- It depends on the speed you are going.
- Speed= Distance/ Time
-What affects thinking distance:
- Speed
- Drugs + alcohol
- Tiredness
- Distractions
- Age
- What affects breaking distance:
-Speed
- Condition of vehicle
- Condition of road. - 15Sun, Earth and Moon- Planets (spheres) in our solar system.
- 16Sun (3)- Sun is a star and a source of everything we need for life. (life and heat energy).
- The Sun is luminous= gives off light.
- When we see light from the moo and other planets, they are reflections of the Suns light. - 17Earth (8)- Where we live.
- 3rd planet from the sun.
- Rotates on its axis every 24 hours.
- If the side we are on faces away from the Sun, it is night.
- If the side we are on faces towards the Sun, it is day.
- The Earth orbits around the Sun every 365 1/4 days (1 year). The orbit of the Sun gives us our years.
- When we are tilted towards the Sun, (on the Earths axis) it is our summer.
- when we are tilted away from the Sun, it is our winter. - 18The Moon (3)- The Moon is the Earth's only natural satellite. A satellite is something that rotates around something else.
- Its gravitational pull is responsible for our tides.
- Orbits the Earths approx. every 29 days (1 month). - 19The Phases of the Moon (8)- Caused by the positions of the Sun, Earth and Moon.
- Half the Moon is always lit up by the Sun.
- When the Moon and Earth are on the same side of the Sun we get a Full Moon.
- When the Moon and the Earth are on opposite sides of the Sun, we get a New Moon (we cannot see the Moon at all)
- In between Full Moon and New Moon is Half Moon. This is sometimes called 1st and 3rd Quarter depending on wether it is Waxing or Waning.
- If you can see LESS THAN HALF THE MOON, it is called a CRESCENT MOON.
- When we see MORE THAN HALF THE MOON, it is called a GIBBOUS MOON.
- Waxing means growing larger and waning means becoming smaller. - 20The Planets (2)- Mercury, Venus, Earth, Mars, (asteroid belt), Jupiter, Saturn, Uranus, Neptune, (Pluto, a 'Dwarf Planet').
- Rotate around the Sun and have different days (time to rotate on their axis) and years (time to rotate around the Sun). - 21Patterns (2)- The further away you get from the Sun, the colder the planets get.
- The closer you are to the Sun, the more dense the planets are.. - 22The Sun (3)- 74% Hydrogen and 24% Helium.
- 98.6% mass of the Solar System.
- Surface temperature: 5,500 degrees celsius. - 23Inner Planets (6)- All solid with a thin atmosphere of gas.
- Mercury is very small and similar in size to the Moon.
- Venus is the hottest planet (greenhouse effect).
- We live on Earth as it has conditions ideal for life.
- Mars has a lot of iron on its surface. It has the biggest volcano in the solar system, Olympus Mons.
- Mercury, Venus, Earth and Mars are all the inner planets. - 24Asteroid Belt (2)- A ring of small to quite large rocks orbiting the Sun.
- Due to Jupiter's gravity, these rocks could not form another planet. - 25Outer Planets (7)- The opposite of outer planets.
- Have small rocky cores surrounded by large amounts of gas that is mainly hydrogen and helium.
- Jupiter is know as the 'failed Sun' because if it was bigger, it could have enough mass to start the nuclear reaction.
- Saturn has rings made of rocks and ice.
- Uranus rotates on its side.
- Neptune is blue due to liquid methane.
- Anything that is mainly affected by the Sun's gravity is considered part of our solar system. - 26Conditions for Life (3)- Earth has the right conditions for life as it has carbon and water and the right amount of energy.
- Carbon forms many different stable compounds.
- Water is also another good compound as it dissolves mother types of compounds and can move energy around living things. - 27Solar Eclipses (3)- The Moon passes between the Earth and the Sun.
- The Sun's light is blocked to the Earth.
- A shadow falls on Earth in daytime. - 28Lunar Eclipses (2)- When the Earth casts a shadow on the Moon.
- The red colour is caused by sunlight going through Earth's atmosphere, - 29Beyond Our Solar System (3)- The Sun is one of the stars in our galaxy called the Milky Way.
- The stars orbit through a black hole.
- Billions of galaxies = the universe. - 30Static Electricity (5)- Static means still.
- Electricity consists of moving charged particles called electrons.
- We rubbed the electrons on our clothes onto the balloon. Then we held the balloon above our hair. Some of the hair was attracted to the balloon. This is because the balloon has lots of electrons and electrons are negative. Negative objects repel other negative objects.
- Hair consists of atoms with a positive nucleus and negative electrons around the outside.
- When the negative balloon goes near the hair atoms, the negative electrons in the hair are repelled. Only the positive middle of the hair atoms are left behind so the hair around the balloon becomes positive. The negative balloon attacks the positive hair. - 31Electric Circuits (6)- We need a complete loop or circuit to allow a flow of current.
- An electric circuit can be turned on and off using a switch.
- A cell is needed to push the electrons around the circuit. This creates a flow of current.
- The cell converts chemical energy into electrical energy and a bulb converts electrical energy into heat and light energy.
Metals are good conductors of electricity. That is why we use metal wires to create circuits.
- When we put more than one cell together, we call it a battery. - 32Measuring and Changing Current (4)- Current is a flow of electrons.
- Current is measured using an ammeter.
- We put an ammeter is series with the component.
- We can change the current by changing the voltage or by adding or taking away components. - 33Resistance (3)- Resistance means the opposite to the flow or charge.
- Components like bulbs and resistors increase the resistance.
- The higher the resistance the lower the current. - 34Series Circuit (3)- The electrons only flow around a single loop.
- Bulbs are dimmer is series than in parallel because they need to share the energy from the electrons.
- If one of the bulbs break, the circuit is broken and all the other bulbs will go out. - 35Parallel Circuits (3)- Parallel circuits have 2 or more different loops that electrons can flow around.
- Bulbs are brighter in parallel because each electron can give all its energy to each component versus sharing.
- If 1 bulb breaks, the others will stay on. - 36Voltage in Series and Parallel (5)- Voltage is a way of measuring how much energy the cells give to the electrons.
- Voltage is measured using a voltmeter.
- A voltmeter is always measured id parallel with the component so that you can measure the amount of energy the electrons have before and after the component.
- Voltage is always shared between components in a series circuit.
- Voltage is the same across components in parallel with each other. - 37Electrical Safety (2)- Wires can get very hot if too much electricity flows through them which causes a fire.
- A fuse is a safety device with a piece of wire designed to melt is the current gets too big. This cuts off the electricity.