P3 - Forces For Transport Flashcards
P3 - Forces For Transport
What does the gradient represent on a distance-time graph?
Speed
P3 - Forces For Transport
What does the flat section show on a distance-time graph?
Where it has stopped
P3 - Forces For Transport
What do the steeper sections of a distance-time graph represent?
Steeper gradient, faster it’s going.
P3 - Forces For Transport
What do downhill sections of distance-time graphs show?
(negative gradient) means changed direction and coming back towards starting point.
P3 - Forces For Transport
What do curves in distance-time graphs represent?
Acceleration or deceleration - steepening curve means speeding up. Levelling off curve means slowing down.
P3 - Forces For Transport
What is acceleration?
How quickly speed is changing - can change direction and it would be accelerating (with or without changing speed).
P3 - Forces For Transport
What does the gradient represent on a speed-time graph?
Acceleration
P3 - Forces For Transport
What do the flat sections of a speed-time graph represent?
Steady speed.
P3 - Forces For Transport
What does a steep gradient mean on a speed-time graph?
Steeper gradient, greater acceleration/deceleration.
P3 - Forces For Transport
What do uphill (/) sections of a speed-time graph represent?
Acceleration
P3 - Forces For Transport
What do the downhill sections of a distance-time graph represent?
Deceleration
P3 - Forces For Transport
What is the area under any section of a speed-time graph?
Distance travelled in that time interval.
P3 - Forces For Transport
What does a curve mean in a speed-time graph?
Non-uniform/changing acceleration or deceleration.
P3 - Forces For Transport
What are the 6 different forces (we need to know for GCSE)?
Gravity/weight, reaction force (from a surface, acts upwards), Thrust/push/pull, drag/air resistance or friction, lift and tension.
P3 - Forces For Transport
What causes acceleration?
Overalll resultant unbalanced force. Bigger unbalanced force, greater acceleration.
P3 - Forces For Transport
What are the 3 main ways friction occurs?
Between solid surfaces which are gripping. Between solid surfaces that are sliding past each other. Resistance or drag from fluids (liquids or gases).
P3 - Forces For Transport
What happens to friction in fluids?
Friction/Drag always increases with speed.
P3 - Forces For Transport
What is terminal speed?
When object sets off, have much more force accelerating than resistance. As speed increases, resistance increases. Acceleration gradually decreases until resistance is equal to accelerating force - balanced.
P3 - Forces For Transport
What happens if the forces are unbalanced?
Object will accelerate in direction of force. Size of acceleration is decided by: F=ma (Newton’s 2nd Law of Motion)
P3 - Forces For Transport
What factors affect thinking distance?
How fast you’re going, and how tired you are or if you have consumed drugs, alcohol and have distractions or a lack of concentration.
P3 - Forces For Transport
What factors affect braking distance?
How fast you’re going, how heavy vehicle is, how good brakes are, and how good grip is.
P3 - Forces For Transport
What affects grip (tyres)?
Road surface, weather - wet or icy makes it more slippery, tyres themselves (minimum tread depth is 1.6mm).
P3 - Forces For Transport
What is aquaplacing?
Skidding very easily or riding on a layer of water because of bald tyres.
P3 - Forces For Transport
What happens to braking distance as speed doubles?
Relationship is squared so double speed would mean braking distance increases 4 fold (2²)
P3 - Forces For Transport
How crumple zones reduces forces in a crash?
They crumple and change shape on impact, increasing time taken for the car to stop.
P3 - Forces For Transport
What happens if the forces on an object are balanced?
It will keep moving at same speed in same direction.
P3 - Forces For Transport
How do seat belts reduces forces in a crash?
Belt stretches slightly, increasing time taken for wearer to stop. Reduces forces acting on chest. Need replacing after crash.
P3 - Forces For Transport
How do air bags help in a crash?
They slow you down more gradually.
P3 - Forces For Transport
What does the ABS do?
Helps drivers keep control of steering when braking hard. Ordinary brakes lock wheels which causes skidding but ABS automatically pump on and off to stop wheels locking. Also give car shorter braking distance which could prevent collision.
P3 - Forces For Transport
What is gravitational potential energy?
Energy that something has because of its height above ground. Energy used to raise it is ‘stored’, and can be changed to kinetic energy if it falls.
P3 - Forces For Transport
What is kinetic energy?
Energy it has when moving. Depends on both mass and speed. Greater mass, faster it’s going (bigger KE).
P3 - Forces For Transport
What is power?
Measure of how quickly work is being done. Not necessarily force exerted but time taken (shorter = more powerful)
P3 - Forces For Transport
What is fuel consumption?
Usually stated as distance travelled using a certain amount of fuel. Often given as miles per gallon (mpg) or litres per 100km.
P3 - Forces For Transport
What does a low mpg value mean?
High fuel consumption - won’t travel far on a gallon of fuel.
P3 - Forces For Transport
What does fuel consumption depend on?
E.g. size of engine, how car is driven, mass of car, speed it’s driven, road conditions.
P3 - Forces For Transport
Why do some cars use biofuels?
Made from plants and organic waste - renewable. Give out CO₂ but it is also taken in by growing plants - no overall increase. Doesn’t produce as much other pollution but producing car still produces pollution.
P3 - Forces For Transport
What are the drawbacks of solar powered/hybrid cars?
Expensive to make and buy, pollution created in production, limited performance at minute.
P3 - Forces For Transport
Speed
What does the gradient represent on a distance-time graph?
P3 - Forces For Transport
Where it has stopped
What does the flat section show on a distance-time graph?
P3 - Forces For Transport
Steeper gradient, faster it’s going.
What do the steeper sections of a distance-time graph represent?
P3 - Forces For Transport
(negative gradient) means changed direction and coming back towards starting point.
What do downhill sections of distance-time graphs show?
P3 - Forces For Transport
Acceleration or deceleration - steepening curve means speeding up. Levelling off curve means slowing down.
What do curves in distance-time graphs represent?
P3 - Forces For Transport
How quickly speed is changing - can change direction and it would be accelerating (with or without changing speed).
What is acceleration?
P3 - Forces For Transport
Acceleration
What does the gradient represent on a speed-time graph?
P3 - Forces For Transport
Steady speed.
What do the flat sections of a speed-time graph represent?
P3 - Forces For Transport
Steeper gradient, greater acceleration/deceleration.
What does a steep gradient mean on a speed-time graph?
P3 - Forces For Transport
Acceleration
What do uphill (/) sections of a speed-time graph represent?
P3 - Forces For Transport
Deceleration
What do the downhill sections of a distance-time graph represent?
P3 - Forces For Transport
Distance travelled in that time interval.
What is the area under any section of a speed-time graph?
P3 - Forces For Transport
Non-uniform/changing acceleration or deceleration.
What does a curve mean in a speed-time graph?
P3 - Forces For Transport
Gravity/weight, reaction force (from a surface, acts upwards), Thrust/push/pull, drag/air resistance or friction, lift and tension.
What are the 6 different forces (we need to know for GCSE)?
P3 - Forces For Transport
Overalll resultant unbalanced force. Bigger unbalanced force, greater acceleration.
What causes acceleration?
P3 - Forces For Transport
Between solid surfaces which are gripping. Between solid surfaces that are sliding past each other. Resistance or drag from fluids (liquids or gases).
What are the 3 main ways friction occurs?
P3 - Forces For Transport
Friction/Drag always increases with speed.
What happens to friction in fluids?
P3 - Forces For Transport
When object sets off, have much more force accelerating than resistance. As speed increases, resistance increases. Acceleration gradually decreases until resistance is equal to accelerating force - balanced.
What is terminal speed?
P3 - Forces For Transport
Object will accelerate in direction of force. Size of acceleration is decided by: F=ma (Newton’s 2nd Law of Motion)
What happens if the forces are unbalanced?
P3 - Forces For Transport
How fast you’re going, and how tired you are or if you have consumed drugs, alcohol and have distractions or a lack of concentration.
What factors affect thinking distance?
P3 - Forces For Transport
How fast you’re going, how heavy vehicle is, how good brakes are, and how good grip is.
What factors affect braking distance?
P3 - Forces For Transport
Road surface, weather - wet or icy makes it more slippery, tyres themselves (minimum tread depth is 1.6mm).
What affects grip (tyres)?
P3 - Forces For Transport
Skidding very easily or riding on a layer of water because of bald tyres.
What is aquaplacing?
P3 - Forces For Transport
Relationship is squared so double speed would mean braking distance increases 4 fold (2²)
What happens to braking distance as speed doubles?
P3 - Forces For Transport
They crumple and change shape on impact, increasing time taken for the car to stop.
How crumple zones reduces forces in a crash?
P3 - Forces For Transport
It will keep moving at same speed in same direction.
What happens if the forces on an object are balanced?
P3 - Forces For Transport
Belt stretches slightly, increasing time taken for wearer to stop. Reduces forces acting on chest. Need replacing after crash.
How do seat belts reduces forces in a crash?
P3 - Forces For Transport
They slow you down more gradually.
How do air bags help in a crash?
P3 - Forces For Transport
Helps drivers keep control of steering when braking hard. Ordinary brakes lock wheels which causes skidding but ABS automatically pump on and off to stop wheels locking. Also give car shorter braking distance which could prevent collision.
What does the ABS do?
P3 - Forces For Transport
Energy that something has because of its height above ground. Energy used to raise it is ‘stored’, and can be changed to kinetic energy if it falls.
What is gravitational potential energy?
P3 - Forces For Transport
Energy it has when moving. Depends on both mass and speed. Greater mass, faster it’s going (bigger KE).
What is kinetic energy?
P3 - Forces For Transport
Measure of how quickly work is being done. Not necessarily force exerted but time taken (shorter = more powerful)
What is power?
P3 - Forces For Transport
Usually stated as distance travelled using a certain amount of fuel. Often given as miles per gallon (mpg) or litres per 100km.
What is fuel consumption?
P3 - Forces For Transport
High fuel consumption - won’t travel far on a gallon of fuel.
What does a low mpg value mean?
P3 - Forces For Transport
E.g. size of engine, how car is driven, mass of car, speed it’s driven, road conditions.
What does fuel consumption depend on?
P3 - Forces For Transport
Made from plants and organic waste - renewable. Give out CO₂ but it is also taken in by growing plants - no overall increase. Doesn’t produce as much other pollution but producing car still produces pollution.
Why do some cars use biofuels?
P3 - Forces For Transport
Expensive to make and buy, pollution created in production, limited performance at minute.
What are the drawbacks of solar powered/hybrid cars?