Stuff To Know Flashcards
What is speed
Speed is the rate of change of distance with time. It is a scalar quantity.
What is velocity?
Velocity is speed in a particular direction. It is a vector quantity.
Scalar and vector quantities
Vector quantities have magnitude and direction but scalar quantities only have magnitude
What is weight
Weight is due to the gravity acting on a mass.
What is mass?
Mass is a measure of the matter in an object and depends on the number of atoms it contains and the size of these atoms.
What is inertia?
Inertia is the tendency of a mass to resist changes in its motion. The greater the inertia the more difficult it is to start or stop the moving object or to change its direction of motion or to accelerate it.
What is terminal velocity?
The maximum constant velocity reached by a falling object which occurs when the weight of an object (downwards) is equal to the air resistance (upwards)
Moment of a force definition
The turning effect of a force about a pivot and is the product of the force and the perpendicular distance form the pivot to the line of action of the force
Principle of moments
When an object is in equilibrium, the sum of the clockwise moments about the pivot equals the sum of the anti-clockwise moments about the same point
Conditions for equilibrium
When there is no resultant force and no resulting turning effect, a system is in equilibrium
Renewable source of energy
A renewable source of energy is one that can be replaced naturally as fast as it is used so it will not run out
Non-renewable source of energy
A non-renewable source of energy is one that cannot be replaced as fast as its being used so it will run out
