physics

• What is the definition of energy in physics?

  Energy is an idea that tells us what will happen when objects interact in a system
• What is the principle of conservation of energy?

  Total energy in any interaction is always conserved
• How is kinetic energy calculated?

  Kinetic energy is calculated with $E =$$\frac{1}{2} mv^2$
• What are the different stores of energy mentioned?

  Kinetic energy, gravitational potential energy, elastic potential energy, thermal energy, and chemical potential energy
• What does gravitational potential energy depend on?

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

  Gravitational potential energy is calculated with $E =$$mgh$
• What does the specific heat capacity tell us?

  Specific heat capacity tells us how much energy is needed to raise 1 kilogram of a substance by 1° Celsius
• What is the equation for change in thermal energy?

  Change in thermal energy is calculated with $E =$$mc\Delta T$
• What happens to particles when thermal energy increases?

  Particles move faster as thermal energy increases
• What is the relationship between energy transfer and closed systems?

  In a closed system, no energy is lost to the surroundings
• How is energy transferred in a system?

  Energy must be transferred from one object or store to another for any interaction to occur
• How can we equate gravitational potential energy and kinetic energy in a roller coaster scenario?

  Gravitational potential energy lost equals kinetic energy gained
• What is the specific heat capacity practical method?

  Heat a material, measure temperature change, and calculate specific heat capacity
• What happens to energy if a roller coaster has more gravitational potential energy at the top than kinetic energy at the bottom?

  Energy must have been lost to the surroundings, indicating it is not a closed system
• What is the equation for power in terms of energy and time?

  Power is calculated with $P =$$\frac{E}{t}$
• What does a power supply of 200 watts mean?

  It uses 200 joules of energy every second
• How do you calculate energy used in a minute from power?

  Energy is calculated with $E =$$P \cdot T$, where T is in seconds
• What is efficiency in terms of energy?

  Efficiency is the ratio of useful energy output to total energy input
• How do you calculate efficiency as a percentage?

  Multiply the efficiency ratio by 100
• What happens to heat in poorly insulated buildings?

  A lot of heat can be lost through walls, windows, doors, and roofs
• What are finite energy sources?

  Finite energy sources include fossil fuels and nuclear fuel
• What are renewable energy sources?

  Renewable energy sources include wind power, hydroelectric power, and solar panels
• What is electricity defined as?

  Electricity is the flow of charge, typically electrons
• How can you practically measure insulation effectiveness?

  Wrap cans with different insulating materials and measure temperature change
• What is the role of a battery in a circuit?

  A battery stores chemical potential energy that is converted to electrical energy
• How is current defined in a circuit?

  Current is the movement of charge through a circuit
• What is potential difference (PD)?

  Potential difference tells us how much energy is transferred per coulomb of charge
• How is potential difference measured?

  Potential difference is measured with a voltmeter
• What is the relationship between current and potential difference in a resistor?

  Current is directly proportional to potential difference in a resistor
• What does a straight line on an IV graph indicate about a resistor?

  A straight line indicates that the resistor has constant resistance
• What is Ohm's Law equation?

  Ohm's Law is expressed as $V =$$I \cdot R$
• How can you find the resistance of a component from an IV graph?

  Resistance can be found by rearranging Ohm's Law: $R =$$\frac{V}{I}$
• What does a curved graph for a bulb indicate?

  A curved graph indicates that the resistance of the bulb is changing
• What is the relationship between potential difference (PD) and current (I) in a resistor?

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

  It indicates that the resistor has constant resistance.
• What happens to the graph if the battery is reversed?

  Negative values for both PD and current are obtained, but the line remains straight through the origin.
• What does the gradient of the straight line in a PD versus current graph represent?

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

  V = I × R
• How can you find the resistance of a component from an IV graph?

  By picking a point on the line and rearranging Ohm's Law to R = V / I.
• What happens to the graph when a bulb is used instead of a resistor?

  The graph becomes curved, indicating changing resistance.