Vector Definitions and formulae Flashcards
Define a vector and provide examples.
A vector is a physical quantity that has both magnitude and direction.
- displacement
- velocity
- weight
- acceleration
- force
Define a scalar quantity and provide examples.
A scalar quantity is a physical quantity that has magnitude only.
- distance
- speed
- mass
- time
- energy
Define the term ‘resultant vector’.
The resultant vector is the single vector that has the same effect as the original vectors acting together.
Define the term ‘displacement’. Is displacement a vector or scalar quantity?
Displacement (symbol S) is defined as the change in position of an object relative to a point of origin. It has both magnitude and direction, therefore it is a vector quantity.
Define the term ‘distance’. Is distance a vector or scalar quantity?
Distance is the length of path traveled. It only has magnitude and therefore is a scalar quantity.
Define and give the formula for velocity.
Velocity is the rate of change of position (displacement) in an object. Velocity = Displacement/Change in time. You must specify the direction.
Define and give the formula for speed.
Speed is the rate of change of distance. Speed= distance/change in time.
Give the formulae for average velocity and instantaneous velocity.
Avg= total displacement/total time
Inst= displacement/time. Time being a small interval.
Define and provide the formula for acceleration.
Acceleration is the rate of change in velocity.
Acceleration=change in velocity/change in time.
The object is speeding up if…
The acceleration and velocity are in the same direction (have the same sign).
The object is slowing down if…
The acceleration and the velocity are in opposite directions (opposing signs).
An object is in equilibrium when…
It is acted upon by two or more forces that produce no resultant change in motion. If there is no change in motion then the object is either stationary or moving at constant velocity.
Define the triangular law of forces.
Three forces in equilibrium can be represented by the three sides of a closed triangle taken in order (head to tail).