Topic 1: Distance, Speed and Acceleration Flashcards
What is distance?
How far the object travels or how far away the object is from a fixed point.
What is distance measured in?
Metres (m)
What is time
The interval between two events or the time since the start of the motion.
what is time measured in?
Seconds (s)
What is speed?
A measure of how fast or how slow the object is moving.
What is speed measured in?
metres per second
m/s
miles per hour
mph
What is the equation to calculate speed?
speed=distance/time
What is velocity?
A measure of how fast or how slow the object is moving in a given direction.
What is velocity measured in?
m/s in a given direction.
What is a scalar quantity?
A physical quantity that is completely described by its magnitude.
What is a vector?
A physical quantity described by both its magnitude and direction.
Is speed a scalar quantity or a vector?
Scalar quantity.
Is velocity a scalar quantity or vector?
Vector.
What is acceleration/deceleration?
The rate of change of velocity.
What is acceleration/deceleration measured in?
m/s²
What is the equation for calculating acceleration/deceleration?
acceleration or deceleration = change in velocity/time
What do distance-time graph allow us to measure?
The speed of a moving object.
How are stationary objects represented in a distance-time graph?
Straight horizontal lines.
What is the slope/gradient of a distance-time graph?
The speed of the object.
How do you calculate distance travelled? (for a velocity-time graph)
The area under the velocity-time graph.
What is thinking distance?
The distance the vehicle travels while the driver sees the hazard, thinks about braking and then actually reacts n braking.
What is braking distance?
The distance that the vehicle moves while the brakes are being applied and the vehicle is decelerating to 0m/s.
How do you calculate total stopping distance?
total stopping distance=thinking distance+braking distance
What factors affect thinking distance? (3)
- The velocity of the car
- The reaction time of the driver - can be affected by tiredness, use of alcohol
- The driver may be distracted
What factors affect braking distance? (6)
- Velocity of the car
- Mass of the car
- Condition of the brakes
- Condition of the tyres
- Condition of the road surface
- The weather
What are 3 safety systems built into modern cars?
- Seat belts
- Air bags
- Crumple zones
What is the first way of reducing the force on the occupants?
By reducing the speed of the collision and so reducing the change of the momentum.
What is the second way of reducing the force on the occupants?
By increasing the time for the collision.
What are 2 traffic control measures?
- Speed limits
* Speed bumps
What is displacement?
Distance in a certain direction. (Basically velocity distance).
