Physics Module 3

HideShow resource information
What is the equation for average speed?
1/2(U + V)
1 of 38
How can an objects acceleration change?
If it's speed is changing, it's direction is changing or both together
2 of 38
What is the equation for force?
Force = Mass x Acceleration
3 of 38
What is thinking distance?
The distance travelled between realising there is a need to brake and the brakes starting to act
4 of 38
What is braking distance?
The distance taken to stop once the brakes have been applied
5 of 38
What is the equation for stopping distance?
Stopping Distance = Thinking Distance + Braking Distance
6 of 38
List some factors that effect thinking distance
Lack of concentration / tiredness / greater speed / alcohol or drugs
7 of 38
List some factors that effect braking distance
Road conditions (e.g wet, icy etc) / Car conditions (e.g worn tyres or brakes) / greater speed
8 of 38
On a distance-time graph, what does the gradient represent?
Speed
9 of 38
On a speed-time graph, what does the gradient represent?
Acceleration
10 of 38
A car with high fuel consumption is bad for the environment. Why?
It means it requires more fuel and so more fossil fuel which is a finite source and contributes to the greenhouse effect as when burnt, it releases CO2
11 of 38
What is the equation for work done?
Work Done (J) = Force x Distance (moved in direction of force)
12 of 38
What is the equation for weight?
Weight (N) = Mass (kg) x Gravitational Force (m/s2)
13 of 38
Power is what?
A measurement of how quickly work is being done
14 of 38
What are the equations for power?
Power (W) = Work Done (J) / Time Taken (s) OR Power = Force x Speed
15 of 38
What is the equation for kinetic energy?
1/2mv2
16 of 38
How can you change the kinetic energy of an object?
Increase the object's mass or speed
17 of 38
braking force x braking distance =
Change in Kinetic Energy
18 of 38
List some fuels to power vehichles
Petrol / Diesel / Liquid Bio-fuels / Bio-gas / Electricity / Solar Power
19 of 38
For fuel, we rely on petrol and diesel. Why is this bad?
Fossil fuels are finite as they take millions of years to form. If we don't have an alternative, we'll be stuck for fuel to power everyday items. Also fossil fuels release CO2 which is contributes to the greenhouse effect
20 of 38
Why are bio-fuels and solar power preferable to fossil fuels?
They are renewable sources of energy and give off little pollution
21 of 38
Do electrically powered cars pollute the environment?
Not at the point of use. However, battery powered cars need recharging and the electricity comes from a power station which does give off pollution
22 of 38
List the advantages of bio-fuel and solar powered cars
Reduce pollution at point of use / could lead to an overall reduction in CO2 emissions
23 of 38
List the disadvantage of bio-fuel and solar powered cars
They produce pollution when being produced/manufactured
24 of 38
How can the shape of an object effect fuel consumption?
If a car is less aerodynamic, it will take more energy to reach or maintain a higher speed and so more fuel is used up
25 of 38
What is the equation for momentum?
Momentum (kgm/s) = Mass x Velocity (m/s)
26 of 38
Momentum is a what quality meaning you must always do what?
Momentum is a vector quality meaning it must have direction as well as a numerical answer
27 of 38
How can we use momentum to calculate force?
Force = Change in Momentum / Time
28 of 38
How do safety procedures work?
A sudden change of momentum can cause a large force to be exerted which can cause injuries on passengers. Safety procedures spread the change of momentum over a longer time and so minimizes injuries as there is a lower force exerted
29 of 38
Increase stopping/collision time / Increase stopping/collision distance / Decrease acceleration
30 of 38
How do crumple zones on a car protect the occupant?
By changing shape in a crash, they absorb energy and increase the time between impact and stopping
31 of 38
What are the problems with seat belts?
They have to be replaced after a crash as the material has stretched and so will be ineffective the next time it is used. Also injuries can be caused by seat belts and can trap someone when car is burning or submerged if the seat belt locks
32 of 38
What does and ABS system do?
They prevent the wheels from locking if a driver brakes hard on slippery surface and so prevents skidding and accidents
33 of 38
How can friction be reduced?
Use a lubricant / make he shape more aerodynamic
34 of 38
What is terminal velocity?
The maximum speed an object can travel at
35 of 38
How do you work out G.P.E?
G.P.E = Mass x Gravitational Field Strength x Height
36 of 38
What is G.P.E?
The energy something has because of its height off the ground. The energy used to raise the object is stored and can be changed into kinetic energy if it falls.
37 of 38
How is kinetic energy linked to G.P.E?
Kinetic Energy Gained = G.P.E Lost (1/2mv2 = mgh)
38 of 38

Other cards in this set

Card 2

Front

How can an objects acceleration change?

Back

If it's speed is changing, it's direction is changing or both together

Card 3

Front

What is the equation for force?

Card 4

Front

What is thinking distance?

Card 5

Front

What is braking distance?