Work And Energy Flashcards
What is needed to do work
What is it measured in
Energy
Energy and work are measured in joules (J)
What factors does the amount of work done depend on
The size of the force in newtons (N)
The distance the object is moved in metres in the direction of the force
What is power a measure of
What is the unit of power
Power measures how quickly work is done; the work done per second
Measured in watts (W)
What is kinetic energy
The energy an object has because of it’s movement
Measured in joules
What does kinetic energy depend on
The mass of the object (kg)
The speed on the object (m/s)
What is a disadvantage to biodiesel
Plants that are used to make it are grown in fields that could be used to grow food
What is the trouble with cars powered by electricity
Batteries are charged using electricity generated in power stations that does pollute
Why have aerodynamic cars got lower fuel consumption
Less wind resistance
What needs more work
A small force for a short distance
A big force for a short distance
A big force for a short distance
What needs more work
A big force for a short distance
A big force for a long distance
A big force for a long distance
What is momentum
The measure if an object’s tendency to move in a straight line with constant speed
How can air resistance (drag) increase
More speed
More surface area
At terminal velocity (speed) what two things are equal
Weight=drag
Explain terminal velocity for falling object
It cannot get any faster, falls at constant speed
The forces bare balanced
Air resistance is equal to the weight of the object
Why is there less air resistance higher up in the atmosphere
There are less air molecules therefore less air resistance
They don’t collide as often as there are fewer
