IB Physics HL Study Guide Flashcards

Flashcards based on IB Physics HL study guide covering all core and HL topics including Mechanics, Thermal, Waves, Electricity, Magnetism, Circular Motion, Atomic, Nuclear, and Energy Production.

What are the three important things to remember when writing down the final value of a measurement or calculation?

Use the right unit, use scientific notation or metric multipliers for very large/small numbers, and use the right amount of significant figures.

What are the seven fundamental SI units (though you only need to know six for the course)?

seconds ($s$), meters ($m$), kilograms ($kg$), kelvin ($K$), mole ($mol$), ampere ($A$), and candela (the one not usually required).

What is the fundamental unit for Time?

$$\text{seconds (s)}$$

What is the fundamental unit for Displacement?

$$\text{meters (m)}$$

What is the fundamental unit for Mass?

$$\text{kilograms (kg)}$$

What is the fundamental unit for Temperature?

$$\text{kelvin (K)}$$

What is the fundamental unit for Amount of substance?

$$\text{mole (mol)}$$

What is the fundamental unit for Current?

$$\text{ampere (A)}$$

How is the unit for speed ($v$) derived?

$$\frac{\text{unit of displacement}}{\text{unit of time}} = \frac{[m]}{[s]} = m\,s^{-1}$$

What is the calculation and unit for Force ($F$)?

$F = m \times a$, resulting in $kg\,m\,s^{-2}$, known as the newton ($N$).

What is the calculation and unit for Charge ($q$)?

$q = I \times t$, resulting in $A\,s$, known as the coulomb ($C$).

What is the unit for Electric field ($E$) in fundamental SI units?

$$kg\,m\,s^{-3}\,A^{-1}$$

How many orders of magnitude larger is 1500 m compared to 15 m?

Two orders of magnitude (100 times larger).

What is the standard form for scientific notation?

$N \times 10^{m}$, where $1 \leq N < 10$ and $m$ is the order of magnitude.

What is the symbol and power for the metric prefix 'pico'?

$p$; $10^{-12}$

What is the symbol and power for the metric prefix 'femto'?

$f$; $10^{-15}$

What is the symbol and power for the metric prefix 'atto'?

$a$; $10^{-18}$

What is the symbol and power for the metric prefix 'zepto'?

$z$; $10^{-21}$

What is the symbol and power for the metric prefix 'yocto'?

$y$; $10^{-24}$

What is the symbol and power for the metric prefix 'tera'?

$T$; $10^{12}$

What is the symbol and power for the metric prefix 'peta'?

$P$; $10^{15}$

What is the symbol and power for the metric prefix 'exa'?

$E$; $10^{18}$

What is the symbol and power for the metric prefix 'zetta'?

$Z$; $10^{21}$

What is the symbol and power for the metric prefix 'yotta'?

$Y$; $10^{24}$

What are the four rules for determining significant figures?

1. Non-zero digits are significant. 2. Zeros between non-zeros are significant. 3. Zeros after non-zeros are significant ONLY if after a decimal point. 4. Zeros before non-zeros are NOT significant.

How many significant figures does 809.0 have?

4 significant figures.

How many significant figures does 0.002 have?

1 significant figure.

How many significant figures does 04.400 have?

4 significant figures.

What is the rule for significant figures when adding or subtracting?

Take the least number of decimal places used in the calculation.

What is the rule for significant figures when multiplying or dividing?

Take the least number of significant figures used in the calculation.

How should a value of 3.65 be expressed if read from a graph with grid units of 0.1?

$$3.7$$

What is absolute uncertainty?

The uncertainty in a measurement expressed as an absolute value (e.g., $\pm 0.5$).

What is fractional uncertainty?

$$\frac{\text{absolute uncertainty}}{\text{measurement}}$$

What is percentage uncertainty?

$$\frac{\text{absolute uncertainty}}{\text{measurement}} \times 100\%$$

How do you calculate uncertainty when adding or subtracting values ($y = a + b$)?

Sum the absolute uncertainties ($\Delta y = \Delta a + \Delta b$).

How do you calculate uncertainty when multiplying or dividing values ($y = ab$ or $y = a/b$)?

Sum the fractional uncertainties ($\frac{\Delta y}{y} = \frac{\Delta a}{a} + \frac{\Delta b}{b}$).

How do you calculate uncertainty for an exponent ($y = a^{n}$)?

Multiply the fractional uncertainty by $n$ ($\frac{\Delta y}{y} = |n \frac{\Delta a}{a}|$).

What does the gradient of a linear graph ($y = ax + b$) represent?

How steep the line is ($a$).

What does the intercept of a graph represent?

Where the line crosses the x- or y-axes.

How do you determine the absolute uncertainty from an error bar on a graph?

Measure the length of the error bar and divide by 2.

How do you calculate the gradient ($a$) between two points on a graph?

$$a = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$$

What are random errors?

Errors that affect each measurement in a random manner, caused by instrument fluctuations or surroundings. They are reduced by repeated readings.

What are systematic (or zero) errors?

Errors that affect each measurement in the same manner, reduced by instrument calibration; they can be determined by checking the intercept.

What is the definition of a vector?

A quantity with both a magnitude and a direction.

What is the definition of a scalar?

A quantity which has only a magnitude.

Is energy a vector or a scalar?

Scalar.

How do you resolve a vector $A$ into horizontal ($A_{h}$) and vertical ($A_{v}$) components given an angle $\vartheta$?

$A_{h} = A \cos(\vartheta)$ and $A_{v} = A \sin(\vartheta)$

What formula links the total length of a vector to its components?

$$|A| = \sqrt{A_{h}^{2} + A_{v}^{2}}$$

What is the difference between displacement and distance?

Displacement is a vector stating an object's change in position; distance is a scalar.

What is the difference between velocity and speed?

Velocity is a vector stating the rate of change of displacement; speed is a scalar.

What is acceleration?

A vector quantity stating the rate of change of velocity.

What is uniformly accelerated motion?

Motion of a body under constant (possibly zero) acceleration.

What is the SUVAT equation for final velocity ($v$) involving initial velocity ($u$), acceleration ($a$), and time ($t$)?

$$v = u + at$$

What is the SUVAT equation for displacement ($s$) involving initial velocity ($u$), time ($t$), and acceleration ($a$)?

$$s = ut + \frac{1}{2} at^{2}$$

What is the SUVAT equation linking displacement ($s$) to initial ($u$) and final ($v$) velocity and time ($t$)?

$$s = \frac{(u + v)t}{2}$$

What is the SUVAT equation linking final velocity ($v$), initial velocity ($u$), acceleration ($a$), and displacement ($s$)?

$$v^{2} = u^{2} + 2as$$

What is relative velocity?

The velocity of one body in the rest frame of another ($v = v_{o} + v_{r}$).

In a velocity-time graph, what does the gradient represent?

Acceleration ($a$).

In a velocity-time graph, what does the area under the line represent?

Distance (or displacement) covered ($s$).

How do you handle projectile motion problems?

Break the motion into independent horizontal ($x$) and vertical ($y$) components.

In projectile motion, what is the acceleration in the horizontal direction?

$0$ (neglecting air resistance).

In projectile motion, what is the acceleration in the vertical direction?

Gravitational acceleration ($g = 9.81\,m/s^{2}$).

What is the formula for the horizontal displacement ($s_{x}$) of a projectile?

$$s_{x} = s_{x,0} + v_{x} t$$

What is terminal velocity?

The maximum speed a freely falling object reaches when air resistance equals its weight.

What is a point particle?

An object represented as a single point, even if it is a rigid body.

What is a free body diagram?

A diagram showing all different forces acting on a body using arrows.

State Newton's 1st law.

If the net force ($F$) on an object is zero, its velocity ($v$) remains constant ($a = 0$).

State Newton's 2nd law.

The net force ($F_{net}$) of an object is equal to its mass ($m$) times its acceleration ($a$): $F_{net} = ma$.

State Newton's 3rd law.

Every action has an equal but opposite reaction: $\mathbf{F}_{a} = -\mathbf{F}_{b}$.

In what direction do drag forces act?

Opposite to the direction of motion.

In what direction does the normal (reaction) force act?

Perpendicular to the surface.

What is static friction ($F_{f}$)?

Friction that must be overcome to start moving: $F_{f} \leq \mu_{s} R$, where $\mu_{s}$ is the coefficient of static friction.

What is dynamic friction ($F_{f}$)?

Friction experienced when an object is already moving: $F_{f} = \mu_{d} R$, where $\mu_{d}$ is the coefficient of dynamic friction.

State the principle of conservation of energy.

In any closed system, the total amount of energy always remains the same ($E_{1} = E_{2}$).

What is the formula for kinetic energy ($E_{k}$)?

$$E_{k} = \frac{1}{2} mv^{2}$$

What is the formula for gravitational potential energy ($E_{g}$)?

$$E_{g} = m g \Delta h$$

What is the formula for elastic potential energy ($E_{e}$)?

$$E_{e} = \frac{1}{2} k \Delta x^{2}$$

What are the two ways to define work ($W$)?

1. The force exerted in the direction of motion: $W = Fs \cos(\vartheta)$. 2. The change in energy ($\Delta E$) between two points.

In a force-distance graph, what represents the work done?

The area under the curve.

What is the unit of power ($P$)?

$\text{watt (W)}$ or $J/s$.

What are the two formulas for power ($P$)?

$P = \frac{\Delta E}{\Delta t}$ and $P = F v$

What is the formula for efficiency using power?

$$\text{Efficiency} = \frac{\text{useful power output}}{\text{total power input}} \times 100\%$$

What is momentum ($p$)?

The mass of an object times its velocity: $\mathbf{p} = m\mathbf{v}$.

How is force related to momentum?

Force is the rate of change of momentum: $F = \frac{\Delta p}{\Delta t}$, provided mass is constant.

What is impulse ($\Delta p$)?

The change in momentum of an object: $\Delta p = F \Delta t$.

State the law of conservation of momentum.

When the external force on a system is zero, the total momentum is conserved.

What is an elastic collision?

A collision where both momentum and kinetic energy are conserved.

What is an inelastic collision?

A collision where momentum is conserved, but kinetic energy is not.

Define temperature.

A measure of how hot something is, or a measure of the average kinetic energy of molecules.

What is the conversion from Celsius ($^{\circ}C$) to Kelvin ($K$)?

$$K = ^{\circ}C + 273$$

Define heat.

The amount of energy transferred from a warmer to a cooler object ($J$).

Define internal energy.

The sum of all kinetic energy of molecules plus the intermolecular potential energy.

What happens to temperature during a change in potential energy (phase change)?

The temperature stays constant.

What is Avogadro's constant ($N_{A}$)?

$6.02 \times 10^{23}\text{ mol}^{-1}$.

What is a mole?

The SI unit for measuring the amount of a substance; one mole contains $6.02 \times 10^{23}$ molecules.

How do you calculate the number of moles ($n$)?

$n = \frac{N}{N_{A}}$, where $N$ is the number of molecules and $N_{A}$ is Avogadro's constant.

What are intermolecular forces?

Bonds that hold molecules together; they change strength during phase transitions.

Define specific heat capacity ($c$).

The energy needed to warm up $1\,kg$ of matter by $1\,^{\circ}C$. Formula: $Q = mc\Delta T$.

Define specific latent heat ($L$).

The energy needed for $1\,kg$ of matter to go through a phase transition. Formula: $Q = mL$.

On a temperature-time graph, what does a steeper slope indicate regarding specific heat capacity?

A steeper slope indicates a smaller specific heat capacity.