dunno Flashcards
Q: What is energy?
A: Energy is the ability to do work, measured as the ability to cause change or perform work.
Q: What are the four main types of energy stores?
A: Kinetic energy, gravitational potential energy, elastic potential energy, and thermal energy.
Q: State the law of conservation of energy.
A: Energy cannot be created or destroyed, only converted from one form to another.
Q: What is the equation for kinetic energy?
A: e = 1/2 mv^2
Q: What is the equation for gravitational potential energy?
A: e = mgh
Q: What is the equation for elastic potential energy?
A: e = 1/2kx^2 where k = spring constant
Q: What is the equation for thermal energy?
A: e = mc delta theta
Q: Define specific heat capacity.
A: The amount of energy required to raise the temperature of 1 kg of a substance by 1 degree Celsius.
Q: What is the formula for power?
A: p = e/t
Q: How is efficiency calculated?
A: efficiency = useful energy out / total energy in
Q: List examples of finite (non-renewable) energy sources.
A: Fossil fuels (coal, oil, gas) and nuclear fuel (uranium).
Q: List examples of renewable energy sources.
A: Wind power, solar panels, hydroelectric power, geothermal power, and biofuel.
Q: What is electricity?
A: The flow of charges (like electrons) that carry energy from a source to a component.
Q: What is potential difference (voltage)?
A: The energy transferred per unit of charge, measured in volts
Q: What is the formula for potential difference?
A: v = e/Q where q is charge
Q: What is the formula for current?
A: i = q/t
Q: What is resistance?
A: The opposition to the flow of charge or current in a component.
Q: State Ohm’s Law.
A: v = IR
Q: How do series circuits distribute voltage, current, and resistance?
A: Voltage is shared, current is the same, and total resistance is the sum of individual resistances.
Q: How do parallel circuits distribute voltage, current, and resistance?
A: Voltage is the same, current is shared, and total resistance is less than the lowest individual resistance.
Q: What is the relationship between power, voltage, and current?
A: p = vi
Q: What is alternating current (AC)?
A: Current that changes direction periodically, as in mains electricity (50 Hz in the UK).
Q: What is direct current (DC)?
A: Current that flows in one direction, as in batteries.
Q: What is a fuse, and what does it do?
A: A safety device in a circuit that melts when the current exceeds a specified value to prevent damage.
Q: How does nuclear fission release energy?
A: A nucleus splits into smaller nuclei, releasing energy as kinetic energy.
Q: What is nuclear fusion?
A: A process where light nuclei combine to form a heavier nucleus, releasing energy.
Q: What is the half-life of a radioactive isotope?
A: The time it takes for the activity of a radioactive isotope to decrease by half.
Q: What are the three types of radiation?
A: Alpha, beta, and gamma radiation.
Q: What is the equation for density?
A: p = m/v
Q: What is the particle model of matter?
A: All matter is composed of tiny particles (atoms/molecules) in constant motion.
Q: What is specific latent heat?
A: The energy required to change the state of 1 kg of a substance without changing its temperature.
