P3 - Power, Fuel Consumption and Emissions, Fuel for Cars, Forces and Acceleration Flashcards
What happens if the forces on a moving object are all balanced?
If the forces on an moving object are all balanced, then it will keep moving at the same speed, and in the same direction
What can you assume about an object moving at a constant speed without change in direction?
You can assume that the forces must all be balanced ( force arrows are all the same size ).
What is the resultant force of an object moving at a steady speed?
To keep going at a steady speed, there must be zero resultant force (overall).
What happens if there is an unbalanced horizontal/vertical force?
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 ).
What is the size of the acceleration decided by?
The size of the acceleration is decided by: F = MA
What are the five forms of acceleration?
Starting Stopping Speeding Up Slowing Down Changing Direction
What will an unbalanced force always produce?
Acceleration in a certain direction.
What is power?
Power is a measure of how quickly work is being done.
What does a powerful machine do?
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.
What is power measure in?
Power is measured in watts ( or Joules per second J/s)
What determines how powerful an engine is?
The size and design of car engines determine how powerful they are.
Why do more powerful engines have higher fuel consumption?
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.
Why are cars with more powerful engines more expensive to run?
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.
Why is a higher fuel consumption engine bad for the environment?
More fuel consuming engines will contribute more to damaging the environment, this is because fossil fuels produce pollutants and therefore pollute the environment.
What is the difference between mpg and low fuel consumption?
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.