paper 1

• What is energy described as in physics?

  Energy is an idea representing interactions
• How is total energy in any interaction characterized?

  Total energy is always conserved
• What can energy be turned into according to the study material?

  Energy can be turned into matter mass
• What are the different stores of energy mentioned?

  Kinetic, gravitational potential, elastic potential
• How is kinetic energy calculated?

  Kinetic energy is calculated with $e =$$\frac{1}{2} mv^2$
• What does gravitational potential energy depend on?

  It depends on mass, height, and gravitational field strength
• What is the formula for gravitational potential energy?

  Gravitational potential energy is $e =$$mgh$
• What does an increase in thermal energy result in?

  Particles moving faster, increasing kinetic energy
• How is thermal energy change calculated?

  Using the equation $e =$$mc\Delta T$
• What is specific heat capacity?

  Energy needed to raise 1 kg by 1°C
• What is chemical potential energy?

  Energy stored in food or fuels
• What must happen for energy to be transferred in a system?

  Energy must move from one object to another
• What is a closed system?

  No energy is lost or gained from surroundings
• What happens to gravitational potential energy as an object falls?

  GPE decreases while kinetic energy increases
• How can we find the speed of an object using energy equations?

  By rearranging the kinetic energy equation
• What does work done against air resistance mean?

  Energy is lost to the surroundings
• What is the equation for power?

  Power is $P =$$\frac{E}{T}$
• What does efficiency measure?

  How much energy is used usefully
• How is efficiency calculated?

  Efficiency is useful energy out divided by total energy in
• What happens to energy in a system with 60% efficiency?

  40% of energy is wasted as heat
• What are finite energy sources?

  Sources that cannot be replenished once used
• What is electricity defined as?

  The flow of charge or charges
• What is potential difference (PD)?

  Energy transferred per coulomb of charge
• How is potential difference measured?

  With a voltmeter connected in parallel
• What does a voltmeter measure across a battery?

  It measures the voltage supplied to electrons
• What is the equation for current?

  Current is $I =$$\frac{Q}{T}$
• What does resistance do in a circuit?

  It resists the flow of charge or current
• How does increasing potential difference affect current?

  It results in a greater current flowing
• What does Ohm's law state?

  Voltage equals current times resistance
• How can resistance be calculated from an IV graph?

  By picking a point and rearranging Ohm's law
• What does a curved graph for a bulb indicate?

  Resistance is changing with current
• What is the relationship between PD and current in a resistor?

  They are directly proportional.
• What does a straight line graph of PD and current indicate?

  It shows constant resistance in a resistor.
• What happens when the battery is reversed in a circuit?

  Negative values for both PD and current occur.
• What does a steeper gradient on a PD-current graph indicate?

  Lower resistance of the resistor.
• What is the equation for resistance according to Ohm's Law?

  V = I × R
• How can resistance be calculated from an IV graph?

  By rearranging Ohm's law to R = V / I.
• What happens to the resistance of a bulb when the PD and current increase?

  The resistance changes and increases.
• Why does the resistance of metals change with increased PD and current?

  Due to increased collisions with vibrating ions.
• What is a characteristic of a diode?

  It allows current to flow in one direction.