Forces and energy Flashcards
What is a system?
A single object or a group of objects
What is efficiency?
The proportion of total energy supplied that ends up in useful energy stores
How can energy be transferred?
+Heating +Forces doing work +Electrical equipment
What happens if a force moves?
+Work is done
What is the equation for work done?
+Work done = force x distance
What is power?
+Power is the rate of energy transfer
+Unit of power is watt (W)
+1 W = 1J/s
What is a force?
+A push or pull on an object that is caused by interacting with something.
+It is a vector (has both size and direction)
+Whenever two objects interact, both objects feel an equal and opposite force (N’s3rd law)
What is a free body force diagram?
+Shows an isolated body (an object or system of its own) and all forces acting on it.
What is the resultant force?
+The overall force on a point or an object.
+Can sometimes be called the net force
What is an object in equilibrium?
When all forces of an object combine to give a resultant force of zero.
What is a moment?
The turning effect of a force.
What is a pivot?
The centre of rotation
What is the equation for a moment?
What are gears?
- Wheels with teeth around their rims.
- Can be used to transfer rotational forces.
How aret the ratio of speeds and the ratio of gears linked?
They are inversely proportional.
What is the equation for power?
