Flashcards
TOPIC I ENERGY AND ELECTRICITY
Cards in this deck (32)
- 1What is an energy transfer?This is when the location of energy changes, when energy moves from one place to another.
- 2What is an energy transformation?This is when energy goes from being one type of energy to another. So the form of energy changes.
- 3Is energy ever lost or created?Energy is never lost or created.
- 4Define gravitational potential energy.This is the energy an object has because of its height above a surface. This is stored energy.
- 5What kind of energy do strings store?Potential mechanical energy
- 6How does an electric bell work?The chemical energy in a cell is transformed into electrical energy, the electromagnet then turns this into kinetic energy by making a metal arm strike the bell. The bell itself, then transforms this into sound energy.
- 7Name 4 good things about electrical energy.1.It is easy to transfer from place to place through power lines supported by pylons.
2.Once electrical energy has made its way through the circuit to the device it is easy to transform into other types of energy.
3.The accuracy of its control is an advantage
4. Unlike burning coal, oil or gas it doesnt leave behind any physical pollution although creating it does. - 8What is a photo-electric cell?A device that transforms light energy directly into electrical energy.
- 9What is "work"?It is a force applied across a distance.
w=f x d - 10What is kinetic energy?If a ball is flying through the air it has kinetic energy, because it is moving. We know it has energy because it can do work on an object upon collision.It can damage the object or move it. The faster the ball moves the more kinetic energy it has
- 11What is the formula for kinetic energy?Kinetic energy=speed squared x mass x 1/2
- 12What is gravitational potential energy?If a book is sitting on a shelf it has gravitational potential energy, The higher above the ground it is the more gravitational potential energy it has. If the book falls the gravitational energy decreases and is transformed into kinetic energy. The more it falls the more kinetic energy it has and the less gravitational energy it has.
- 13What is the formula for gravitational potential energy?gravitational potential energy= mass x gravitational acceleration x height
- 14What is internal/thermal energy?Say there is a cup of coffee, we say it has internal energy. Internal energy is the sum of the potential and kinetic energy of the molecules of the coffee. It has kinetic energy because the particles are constantly moving. It has potential energy because the particles are mutually attracted to each other. The faster the particles vibrate the more internal energy there is. When we measure the temperature of something we are measuring the internal energy of it.
- 15What is chemical energy?Chemical energy is stored in the chemical bonds between atoms and it is released during chemical reactions when these bonds are broken. Our body's glucose has chemical energy it releases when it reacts with oxygen. Fuels have chemical energy they release when burnt.
- 16What is nuclear energy?The energy of the nuclei of an atom, comes from the strong bonds between the particles of a nucleus. The sun, nuclear reactors and the earth's interior all use nuclear reactions as a source of their energy. In the sun, Hydrogen nuclei fuse combine together to helium nuclei in a process called fusion, which releases energy. In the earths interior and nuclear reactors Uranium splits apart in a process called fission.
- 17What is electrical energy?It is the energy of charged particles in an electric field. In an electrical circuit, the energy is transferred bu the moving electrons/electrical current.
- 18Define strain/elastic potential energyObjects have strain energy when their shapes can be changed by being compressed or stretched.
- 19What are 3 rules of energy?1.Energy cannot be created or destroyed.
2.Energy may be transformed but the total energy is always conserved.
3. The total energy at the start of the system and at the end of the system must have the same value. - 20What is electric current?The flow of electrons
- 21What are 5 general rules to remember about current?1.The more cells you add to the circuit, the more current flow.
2.The more bulbs you add to a series circuit, the less current flow.
3.The current in a series circuit is the same at all points
4.The current in a parallel circuit splits when the circuit branches.
5.The current is not used up, it is simply the flow of electrons through conductors in a circuit. - 22What are 2 general rules to remember about voltage?1.In a series circuit the voltage across the cell is the same as the sum of the voltage of the other components.
2.In a parallel circuit the voltage across each individual component can be the same. - 23Where does the energy in a cell come from?When the chemicals inside a cell react with each other, they turn chemical energy into electrical energy. The batter has 2 terminals, the carbon rod which is a positive terminal, and zinc shell which is the negative terminal. When the chemicals in the paste react with the zinc to provide and electric current, the zinc is gradually "eaten away".
- 24Define a series circuit?A circuit where there is only one path for the current to flow through.
- 25Define a parallel circuitA circuit where there are multiple paths for the current to flow through.
- 26Define currentThe amount of electricity flowing through a circuit. and the flow of electrons moving through the circuit.
- 27Define voltage.The push or pressure applied to the electrons moving through a circuit.
- 28Why are high voltages hazardous?Lightning can kill people as can the high voltages transported through power lines and mains electricity in your home.
- 29Define power.The amount of energy an appliance transfers in one second.
- 30What is the formula for Power?Power=energy/time
- 31What is efficiency?REFER TO EFFICENCY PACKET
acting with very little waste.
useful energy/supplied energy - 32What does dissipated mean?It means when the heat energy is spread out into the air so thin that there is nothing we can really do with it, it is lost as heat energy to the surroundings.
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- Form 2 Science Flashcards on TOPIC I ENERGY AND ELECTRICITY, created by Fathima Snaps on 18/07/2017.
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