Motion Graphs Flashcards
Instantaneous Speed
The speed at a single point in time (car speed cameras) record instantaneous speed
Average Speed
total distance / total time
Gradient on d/t graph
Speed of the object
Steep constant gradient (d/t)
Fast constant speed
Shallow constant gradient (d/t)
Gentle constant speed
Zero Gradient (d/t)
Stationary
Increasing gradient (d/t)
Acceleration
Decreasing gradient (d/t)
Deceleration
Gradient on v/t graph
Acceleration
Steep constant gradient (v/t)
Fast constant acceleration
Shallow constant gradient
Gentle constant acceleration
Zero gradient
No acceleration → constant speed
Negative gradient
Deceleration
Distance Travelled
Area under v/t graph
Benefits of using light gates
Remove human reaction times from measuring time → much smaller uncertainty
How Light Gates work
- Beam of infrared light passes between two sensors
- When first beam is broken data logger starts stopwatch
- Stopwatch stops when second beam is broken
- Measuring distance between light gates allows average speed to be calculated
Thinking Distance
Distance travelled while the driver is reacting to stimulus
Braking Distance
Distance travelled from start of braking to stationary
Factors affecting thinking distance
Drugs, alcohol, tiredness, mobile phone use
Factors affecting braking distance
Speed of vehicle, mass of vehicle, condition of brakes/tyres/road, ice/water on road
Stopping Distance
Thinking distance + Braking distance
Final Velocity
v^2 = u^2 + 2as
S
U
V
A
T
distance
initial velocity
final velocity
acceleration
time
