Physics - 9 Motion - 9.1 Speed and Distance-Time Graphs & 9.2 Velocity and Acceleration & 9.3 More About Velocity-Time Graphs & 9.4 Analysing Motion Graphs

Value representative of speed on a distance-time graph

gradient

speed =

distance ÷ time

v =

s ÷ t

Unit of speed

metres per second, m/s

Velocity

speed of an object in a particular direction

Speed vs. velocity [2]

- speed is a scalar and has only magnitude
- velocity is a vector and has direction and magnitude

A steeper gradient means...

higher speed

Displacement

distance and direction of an object's change in position from a starting point

Distance vs. displacement [2]

- distance is a scalar and has only magnitude
- displacement is a vector and has direction and magnitude

Acceleration

rate of change of velocity

[1] acceleration =

change in velocity ÷ time

[1] a =

∆v ÷ t

[2] acceleration =

(final velocity - initial velocity) ÷ time

[2] a =

(v - u) ÷ t

[3] final velocity squared =

initial velocity squared + (2 x acceleration x displacement)

[3] v² =

u² + 2as

Deceleration

negative acceleration, where an object slows down

Value representative of acceleration on a velocity-time graph

gradient

Value representative of displacement on a velocity-time graph

area under the line

gradient =

∆y ÷ ∆x