## Relative Clauses

Relative clauses are the phrases which start with a relative pronoun. While they probably essential to the meaning of a sentence, they are never crucial to the completeness of a sentence. For instance:

The tiger ate my aunt earlier today.

The tiger [that was hungry] ate my aunt earlier today.

Comma phrases are the additional phrases which are set off by a pair of commas. Take the following sentence:

[After escaping], the tiger that was hungry ate my aunt, [who was nice and juicy, earlier today.]

A crucial part of doing well on the SAT Writing section is knowing how to strip away all these secondary phrases to get back to the essence of the sentence.

## Google Fi Review: Cost, Coverage, Speed

Google Fi, as known as Project Fi, launched in 2015 by Google, is a unique SIM card designed for travelers since it could provide calling, texting, and data service in more than 170 countries. Despite it was an internal eSIM card of specific cellphones such as Google Pixel, Google Fi currently supports nearly all popular brands.

With my friend’s recommendation, I ordered a free SIM card from Fi’s official website two months ago, and I’ve been using it as my secondary SIM card wherever in mainland China, Canada, and the United States. After I received the billing receipt of the second month yesterday, I would proudly conclude that I’ve collected enough data for me to compose this review.

## Heat and Thermodynamics

Temperature scales: $\small T(K)=T(^{\circ}C)+273$

Temperature change: $\small Q=mc \Delta T$ (c is the specific heat.)

Phase change: $\small Q=mL$ (L is the latent heat of transformation.)

#### Thermal expansion

$\small \Delta L = \alpha L_{0} \Delta T$ ($\small \alpha$ is the coefficient of linear expansion.)

$\small \Delta V = \beta V_{0} \Delta T$ ($\small \beta$ is the coefficient of volume expansion.)

Continue reading SAT Subject: Physics Cheat Sheet

## AP Physics C Cheat Sheet

### Coulomb’s Law

Force between two point charges: $\small F=\frac{Q_{1}Q_{2}}{4\pi \varepsilon _{0}R^{2}}$

### Electric Fields

Definition of Electric Field: $\small E = \frac{F}{Q}=\frac{Q}{4\pi \varepsilon _{0}R^{2}}$
For a single point: $\small F=qE$

### Potential and Voltage

Definition of electric potential V: $\small V = \frac{U}{Q}$
For a constant electric field: $\small E_{x}=-\frac{\Delta V}{\Delta x}$
Potential due to a point charge at distance a: $\small V(a)= \frac{Q}{4 \pi \varepsilon _{0}a}$

Continue reading AP Physics C Cheat Sheet