paper 1

• the eight energy stores are kinetic, gravitional potential, elastic potential, thermal, chemical, nuclear, magnetic, electrostatic
• the four ways in which energy can be transferred are heating, waves, electric current, forces (mechanically)
• a system is an object or group of objects
• a closed system is a system where no energy can be transferred to or from the surroundings-total energy stays the same
• work done is energy transferred when a force moves an object
• the unit for energy is joules (j)
• one joule of work is the work done when a force of 1N causes an object to move 1m in the direction of the force
• the effect of emitting alpha radiation on the nuleus is it loses 2 protons and 2 neutrons
• when a beta particle is emitted the atomic number increases by 1
• when an alpha particle is emitted the mass number reduces by 4
• when a beta particle is emitted the mass number doesnt change
• work done and power are measured in joules (J) and watts (W) respectively.
• in a convection current hot particle rise and cool at the top and then eventually sink
• the 4 non-renewable resources are coal, oil, gas and nuclear
• specific heat capacity is the amount of energy required to heat 1 kg of a substance by 1 degrees celsius
• when an object is falling the poterntial energy changes to kenetic energy
• the plum pudding model is a ball of positive charge with negative electron studded in
• the penetrating power of gamma radiation in high ( stopped by a few cm of lead)
• internal energy is the amount of energy stored within an object
• energy cannot be created or destroyed
• the graph of current vs potential difference for an ohmic conductor is a straight line through the orign
• isotopes are the same element with the same atomic number but different mass number
• a half life is the time it take for half the radioactive isotopes in a sample to decay
• ernest rutherford used the alpha scattering experiment to determine the nuclear model of the atom
• the penetrating power of beta is medium ( stopped by a few mm of aluminium)
• the effect of emitting beta radiation on the nucleus is neutrons turn into protons
• when alpha particles are emitted the atomic number reduces by 2
• when testing ohms law temperature must stay constant
• to find the resistance of a bulb you will need a cell/battery, bulb, wire, ammeter, voltmeter and a variable resistor
• resistance is how difficult it is for charge to flow through a current
• a diode does not obey ohms law
• a diode only lets current through in one direction
• ohms law states the current through an ohmic conductor is directly proportional to the potential difference across it
• kenetic energy depends on mass and speed
• 2 conductors of specific heat are metal and wood
• the penetrating power of alpha radiation is low ( stopped by paper)
• evaporation has a cooling effect due to energy taken from the liquid for evaporation lowers the temperature
• power is how much energy is transferred to a device in a secons
• renewable means it can be replaced as fast as it is used
• the definition of power is the rate of energy transfer