Distance, speed an acceleration Flashcards
How do you calculate speed?
speed = distance / time
How do you calculate acceleration?
acceleration = change in velocity / time
How do you interpret a distance-time graph?
The slope of the graph indicates the speed
upwards slope = constant speed
downwards slope = constant speed, but going back towards the starting point
flat slope = stationary
an increasingly steep slope = accelerating
How do you interpret a speed-time graph?
The slope of the graph indicates the acceleration
upwards slope = constant high acceleration
downwards slope = constant deceleration
flat slope = constant speed
an increasingly steep slope = increasing acceleration
The area underneath the graph represents the distance travelled
What is thinking distance?
The distance travelled whilst reacting to a situation
What is braking distance?
The distance travelled after the brakes are applied before the car comes to a full stop
How do you calculate thinking distance?
Speed x reaction time
How do you calculate overall stopping distance?
thinking distance + braking distance
What factors affect thinking distance?
- tiredness
- drugs
- alcohol
- distractions
What factors affect braking distance?
- poor road/weather conditions, such as icy roads
- speed
- poor vehicle conditions, such as faulty tires or brakes
- the car’s mass
How do cares keep you safe in the event of a crash?
Features such as seatbelts, airbags increase the time taken for the collision to affect the passengers, which decreases the rate of change in momentum and decreases the force of collision on people within the car.
