10PS Flashcards
vector
A quantity with both magnitude and direction.
scalar
A quantity with magnitude only (no direction).
reference point
The point relative to which all measurements are taken.
reference frame
A coordinate system with an origin and directions used when taking measurements.
distance
The total path length travelled. Scalar.
displacement
The change in position of an object. A vector pointing from initial position to final position.
speed
The rate of change of distance with respect to time. A scalar.
velocity
The rate of change of displacement with respect to time. A vector.
position
The location of an object using a particular frame of reference. A vector.
instantaneous speed
The speed of an object at a particular moment in time. A scalar equal to the magnitude of instantaneous velocity.
instantaneous velocity
The velocity of an object at a particular moment in time. A vector.
uniform velocity
Velocity is constant and thus not changing. Both magnitude and direction if velocity must not be changing. Acceleration is zero.
acceleration
The rate of change of velocity with respect to time. A vector.
positive acceleration
An object is moving in the positive direction and speeding up OR moving in the negative direction and slowing down.
negative acceleration
An object is moving in the positive direction and slowing down OR moving in the negative direction and speeding up.
deceleration
A word used in everyday language to mean slowing down. Not the same as negative acceleration!
speeding up
The acceleration and velocity vectors are pointing in the same direction. Either they are both positive or they are both negative.
slowing down
The acceleration and velocity vectors are pointing in opposite directions. One is positive and the other is negative.
