Physics Mechanics, Waves, and Electricity Review

Flashcards covering mechanics basics, energy transfer, wave properties, sound, and electrical circuits based on the lecture transcript.

What is the formula for speed?

$$Speed = \frac{Distance}{Time}$$

What is the definition of velocity?

Velocity is speed in a certain direction ($Velocity = \frac{Displacement}{Time}$).

What is the formula for average speed?

$$Average\,Speed = \frac{Total\,Distance}{Total\,Time}$$

How is mass defined?

The amount of matter in an object.

How is weight defined and what is its formula?

The force of gravity on an object with a mass, calculated as $W = m \times g$.

What is the value and unit of gravity ($g$) used in these notes?

$$9.8\,m/s^2$$

What is the formula for density ($\rho$)?

$\text{Density} = \frac{\text{Mass}}{\text{Volume}}$, typically measured in $g/cm^3$ or $kg/m^3$.

How is moment calculated?

$Moment = Force \times \text{perpendicular distance to pivot}$ ($Newton\,meter$ or $Newton\,centimeter$).

What are the two conditions for equilibrium?

1. Resultant force equals zero. 2. Resultant moment equals zero.

What is the formula for pressure ($P$)?

$Pressure = \frac{Force}{Area}$ ($N/m^2$ or $Pascal$).

What is the Law of Conservation of Energy?

Energy is never created nor destroyed but transferred from one form to another.

What is the formula for work done ($W$)?

$Work\,done = Force \times Distance$ (where force and distance are in the same direction, measured in Joules ($J$)).

How is power ($P$) defined?

The rate of doing work or the rate of energy transfer ($P = \frac{Work}{Time}$ or $P = \frac{Energy}{Time}$).

What is the formula for the speed of sound when using an echo?

$$Speed = \frac{2 \times Distance}{Time}$$

What is the definition of frequency ($f$)?

The number of complete waves per second ($Hertz, Hz$).

What is the wave equation relating velocity ($v$), wavelength ($\lambda$), and frequency ($f$)?

$$v = \lambda \times f$$

In electricity, what is the definition of current ($I$)?

The amount of charges passing per second ($I = \frac{Q}{t}$).

What is the definition of potential difference or voltage ($V$)?

The energy given to every charge ($V = \frac{E}{Q}$).

What are the formulas for electrical power ($P$) and energy transferred ($E$)?

$P = V \times I$ and $E = V \times I \times t$.

What is a kilowatt-hour ($kWh$)?

A unit of energy where the power is in kilowatts ($kW$) and the time is in hours ($h$).

What is the formula for the cost of electricity?

$$\text{Cost} = \text{Energy consumed in } kWh \times \text{Cost of one } kWh$$