Describing Motion Along a Line Flashcards
state what is meant by distance
how far an object has travelled
distance is a scalar quantity
state what is meant by displacement
how far an object has travelled in a straight line from the starting point to the finishing point and the direction of that line
it is a vector quantity
explain velocity
the speed in a given direction
it is a vector quantity so it has both magnitude and direction
state some typical speeds of everyday situations: walking, running, cycling
walking - 1.5m/s
running - 3m/s
cycling - 6m/s
state the typical value for the speed of sound in air
330m/s
state what is meant by instantaneous speed
the speed of an object in a given moment in time
what are distance time graphs used for?
to represent the motion of an object
describe what is meant by acceleration
the rate of change of velocity
since velocity is a vector, so is acceleration
explain why a skydiver falls at a steady speed
when they jump out of a plane, they may receive terminal velocity
at terminal velocity, the skydiver’s weight is equal in size and opposite in direction to the air resistance on the skydiver
as there is no resultant force, there is no acceleration and the skydiver will fall at a steady speed