# The Physics of a Road Trip - Yeji Kim

Get Started. It's Free
The Physics of a Road Trip - Yeji Kim by

## 3. Scalar quantity

### 3.1. Speed

3.1.1. Rate at which someone or something is able to move or operate

### 3.2. Time

3.2.1. Change, or the interval over which change occurs.

3.2.2. Time interval

3.2.2.1. Difference in time between two clock readings (change of time)

3.2.2.2. Formula: t1-t0

### 3.3. Distance

3.3.1. The length, or size, of the displacement vector

### 3.4. Mass

3.4.1. The quantity of matter in a body regardless of its volume or of any forces acting on it; not equal to weight

3.4.1.1. Symbol: m

3.4.1.2. unit = kilogram (kg)

3.4.1.3. Formula: m = F/a (F = foce, a = acceleration)

### 3.5. Weight

3.5.1. Force exerted on a body by gravity

3.5.1.1. Symbol: W

3.5.1.2. Unit: newton (N)

3.5.1.3. Formula: W = mg (m = mass, g = gravitational acceleration)

## 4. Vector quantity

### 4.1. Velocity

4.1.1. Speed with direction, represented with v with an arrow on top

4.1.2. Average velocity

4.1.2.1. Displacement divided by the time of travel

4.1.2.2. Formula: (df - do) / (tf - to)

4.1.3. Instantaneous velocity

4.1.3.1. Average velocity at a specific instant in time (or over an infinitesimally small time interval); average velocity becomes instantaneous velocity when time interval becomes infinitesimally small

### 4.2. Displacement

4.2.1. Distance and direction between two positions; represented as d

### 4.3. Acceleration

4.3.1. Rate at which velocity changes

4.3.2. Formula:

4.3.3. Constant acceleration

4.3.3.1. When acceleration varies slightly and the average over the entire interval is nearly the same as the instantaneous acceleration at any time

4.3.4. Instantaneous acceleration

4.3.4.1. Acceleration at a specific instant in time

### 4.4. Force

4.4.1. A push or pull exerted on an object having magnitude and direction; it may be either a contact or long-range force

4.4.1.1. Symbol: F

4.4.1.2. Unit: newton (N)

4.4.1.3. Formula: F = ma (m = mass, a = acceleration

4.4.2. Net force

4.4.2.1. The vector sum of all of the forces on an object

## 5. Diagrams

### 5.1. Particle model

5.1.1. Replacing an object by a single point to see its acceleration

### 5.2. Motion diagram

5.2.1. A series of images of a moving object that records its position after equal time intervals

### 5.3. Free-body diagram

5.3.1. A diagram that shows the direction of the force operating on each object