Physics: Quantities and measurement techniques

Scalar

Only magnitude

Vectors

Magnitude and direction

difference of distance and displacement

• distance = measure of how far an object has travelled, regardless of direction

• displacement = the distance between 2 points in a straight line, in a stated direction

difference between speed and velocity

• speed = measure of distance travelled by object per unit time, regardless of direction

• velocity = speed of object in a given direction

define acceleration

how the velocity of an object changes over time

3 ways an object can change its velocity

speed up

slows down

change direction

how can u tell when acceleration is positive

same direction as the motion of the object

describe distance-time graph

• straight line = constant speed

• stationary = horizontal

• gradient = speed

describe speed-time graph

• +ive gradient = constant acceleration

• horizontal = constant speed

• -ve gradient = constant decceleration

formula for weight

mass x gravitational field strength

formula for force

force =mass x accelera

define air resistance

a frictional force produced by collisions with air particles as the object moves through air

relationship of speed and air resistance

speed increases → air resistance increases