IB Physics Exam Definitions

Flashcards for key concepts in IB Physics, covering fundamental units, mechanics, energy, electricity, magnetism, waves, and astrophysics.

What are the 7 SI units of measurement in IB Physics?

1. Distance: Metre; 2. Mass: Kilogram; 3. Time: Second; 4. Temperature: Kelvin; 5. Mol: grams of carbon-12; 6. Electrical current: Ampere; 7. Luminous intensity: Candela.

What does Newton's First Law of Motion state?

An object continues to remain stationary or to move at a constant velocity unless an external force acts on it.

What is the formula for impulse?

Impulse (I) = F∆t, where ∆t is the time for which the force acts.

What is the difference between average speed and instantaneous speed?

Average speed is distance traveled divided by time taken; instantaneous speed is the rate of change of distance at a given instant.

What does the Principle of Conservation of Momentum state?

The total momentum of a system is constant, provided an external force does not act.

What is the formula for Kinetic Energy (Ek)?

Ek = 1/2 mv², where m is mass and v is velocity.

What is Elastic Potential Energy?

Energy associated with the position of an object or its motion.

What is the efficiency equation?

Efficiency (Eff) = Work output / Work input.

What is the difference between elastic and inelastic collisions?

In elastic collisions, kinetic energy is conserved; in inelastic collisions, kinetic energy is not conserved, but momentum is.

What does Coulomb's Law describe?

The force is proportional to the product of the sizes of point charges and inversely proportional to the square of the distance between them.

What is the drift speed in the context of electric circuits?

The slow speed at which the ions move along a conductor.

What is the definition of a Coulomb in Electric Circuits?

The charge transported by a current of one ampere per second.

What is the Bohr Model?

A model that describes electrons traveling in fixed orbits around the nucleus.

What is the Heisenberg Uncertainty Principle?

It is impossible to know both the momentum and the position of a particle at the same time.

What is the difference between renewable and non-renewable energy sources?

Renewable energy sources can be replenished quickly (e.g., solar, wind), while non-renewable sources take geological timescales to be replenished (e.g., fossil fuels).

What is dark matter?

Undetectable matter that emits no radiation and is inferred from gravitational effects on visible matter.

What is the purpose of a transformer?

To change alternating supplies from one potential difference (pd) to another.

What does the term 'superposition' refer to in wave phenomena?

When two or more waves meet, the total displacement is the sum of the individual displacements.

What is the definition of a standing wave?

A standing wave is formed when two travelling waves of equal amplitude and frequency move in opposite directions and superpose.

What is the definition of temperature?

A measure of the average kinetic energy of the particles in a substance.

What is the definition of thermal equilibrium?

The state in which the rate of energy absorbed equals the rate of energy emitted, resulting in no net change in temperature.