P3 - Power, Fuel Consumption and Emissions, Fuel for Cars, Forces and Acceleration

Question 1

What happens if the forces on a moving object are all balanced?

Answer 1

If the forces on an moving object are all balanced, then it will keep moving at the same speed, and in the same direction

Question 2

What can you assume about an object moving at a constant speed without change in direction?

Answer 2

You can assume that the forces must all be balanced ( force arrows are all the same size ).

Question 3

What is the resultant force of an object moving at a steady speed?

Answer 3

To keep going at a steady speed, there must be zero resultant force (overall).

Question 4

What happens if there is an unbalanced horizontal/vertical force?

Answer 4

If there is an unbalanced force, then the object will accelerate in the direction of the force. This is newtons second law of motion; An Unbalanced force will always produce acceleration ( or deceleration ).

Question 5

What is the size of the acceleration decided by?

Answer 5

The size of the acceleration is decided by: F = MA

Question 6

What are the five forms of acceleration?

Answer 6

Starting
Stopping
Speeding Up
Slowing Down
Changing Direction

Question 7

What will an unbalanced force always produce?

Answer 7

Acceleration in a certain direction.

Question 8

What is power?

Answer 8

Power is a measure of how quickly work is being done.

Question 9

What does a powerful machine do?

Answer 9

A powerful machine is not necessarily one which can exert a strong force.
A powerful machine is one which transfers a lot of energy in a short space of time.

Question 10

What is power measure in?

Answer 10

Power is measured in watts ( or Joules per second J/s)

Question 11

What determines how powerful an engine is?

Answer 11

The size and design of car engines determine how powerful they are.

Question 12

Why do more powerful engines have higher fuel consumption?

Answer 12

The larger, or more powerful an engine the more energy it transfers from its fuel every second, so usually it results in a higher fuel consumption.

Question 13

Why are cars with more powerful engines more expensive to run?

Answer 13

Cars with more powerful engines require more fuel, as they burn through more fuel quickly, and because of this they will cost more because fuel costs money.

Question 14

Why is a higher fuel consumption engine bad for the environment?

Answer 14

More fuel consuming engines will contribute more to damaging the environment, this is because fossil fuels produce pollutants and therefore pollute the environment.

Question 15

What is the difference between mpg and low fuel consumption?

Answer 15

Low fuel consumption means that the cars uses less fuel, e.g. does not require much fuel to travel 100km
However a low mpg means that it doesn’t have very good fuel efficiency/has high fuel consumption, it will not travel very far on a gallon of fuel.

Question 16

What does the fuel consumption of a car depend on?

Answer 16

• Size of the engine
• How the car is driven
• Mass of the car
• The speed the car is driven at
• The road conditions
  etc. .

Question 17

How do cars move?

Answer 17

To move a car, the energy from the fuel needs to be changed into kinetic energy ( K.E ).

Question 18

What correlation does fuel consumption have with speed and mass of a car?

Answer 18

The higher the mass of the car, or the greater the speed you want to go, the more energy you will require from fuel to give the car the kinetic energy to move, and so cars with greater masses and cars travelling at greater speeds will use up more fuel, as more energy is required.

Question 19

How does driving style affect fuel consumption?

Answer 19

Driving style will also affect the fuel consumption, faster accelerations need more energy and so use more fuel. Frequent braking and acceleration (e.g. when driving in a town ), will increase the fuel consumption.
Driving in different road conditions will also affect the frequency of braking.

Question 20

How does drag/friction affect fuel consumption?

Answer 20

The energy from the fuel is also needed to do work against friction, e.g. between the tyres and the road, and between the car itself and the air around it. So things like opening the windows or having a roof box will increase a car’s fuel consumption because it increases the air resistance and drag.

Question 21

What are some ways cars are designed to be more fuel efficient?

Answer 21

• More efficient engines

- Streamlined car designs.

Question 22

How do cars contribute to global warming?

Answer 22

• When fossil fuels burn they release emissions, gases like CO2, nitrogen dioxide ( NO2) and water vapour.
• These emissions cause environmental problems like acid rain and global warming.

Question 23

How does fuel consumption affect global warming?

Answer 23

The greater the fuel consumption, the greater amount of pollutants polluting the Earth, and therefore it is worse for the environment.

Question 24

What vehicles require to move?

Answer 24

Vehicles require fuels to move, e.g. most lorries and cars use petrol or diesel.

Question 25

what are petrol and diesel?

Answer 25

Petrol and diesel are fuels that are made from oil, which is a fossil fuel, the emissions that are released when these are burnt can cause environmental problems like acid rain and climate change.

Question 26

Why may we rely on renewable resources in the future for fuels?

Answer 26

• Fossil fuels are non renewable, so one day they will run out.
• They damage the environment too much
  Bio-fuels and solar power may be the fuels of the future which we may have to rely on to power our vehicles.

Question 27

What is an alternative type of fuel to fossil fuel?

Answer 27

Bio-fuels.

Question 28

What are bio-fuels made from?

Answer 28

Bio-fuels are made from plants and organic waste, and are renewable.

Question 29

Why are biofuels renewable?

Answer 29

Because we can keep growing more.

Question 30

How are emissions reduced with biofuels?

Answer 30

Like fossil fuels when burning bio-fuels it gives off carbon dioxide when burnt, but because plants also take in C02, the plants used in biofuels can be replanted, therefore there is no overall increase in the amount of CO2 emissions, infact they could be reduced.
- Burning Bio-Fuels in cars does not produce as much other pollution ( pollution at the point of use ) as fossil fuels.

Question 31

What are electric cars?

Answer 31

Electric cars are cars that use large batteries to power electric motors.

Question 32

What is a disadvantage of Electric cars?

Answer 32

Although they do not release any pollution at the point of use when they are driven, they have to be charged.
The charging station draws electricity from power plants using fossil fuels to produce the electricity ( most power stations currently use fossil fuels ).

Question 33

How do solar powered cars work?

Answer 33

Solar powered cars have solar panels that turn the energy from the sun directly into electricity to power the motor.

Question 34

What are some advantages of using solar powered cars?

Answer 34

• They produce no pollutants at the point of use
• The charging of solar powered cars also produces no pollutants
• Renewable source of energy
• Results in an overall net decrease of CO2 emissions from vehicles.

Question 35

What are disadvantages of using electric/solar powered cars?

Answer 35

• Electric and solar powered cars are expensive to make and buy
• The building of them produces pollution.
• Electric cars have limited performance compared to the fossil fuel alternative, however newer designs with better fuel efficiency are coming out all of the time, such as the recent tesla model S.