topic 1 - motion Flashcards
vector quantity
a physical quantity with magnitude and direction
scalar quantity
a physical quantity with only magnitude and NO direction
examples of vectors (6)
force velocity displacement weight acceleration momentum
examples of scalars (6)
speed distance mass energy temperature time
distance
scalar quantity
how far an object has mooved
displacement
vector quantity
measures the distance and direction in a straight line from an objects starting point to its finishing point
speed
scalar quantity
how fast you’re going
velocity
vector quantity
speed in a given direction
speed (formula)
speed = distance / time
typical speeds
walking
running
cycling
walking 1.4m/s
running 3m/s
cycling 5.5m/s
typical speeds
wind speed
speed of sound in air
wind speed 5-20m/s
speed of sound in air 340m/s
3 ways of measuring speed
light gates (good for short time intervals, and get rid of human error caused by reaction times)
rolling tape measure, markers and a stopwatch
use a video of the moving object
acceleration
the change in velocity in a certain amount of time
average acceleration formula
acceleration = (final velocity - initial velocity) / time
deceleration
negative acceleration
what is the acceleration due to gravity
10m/s^2
acceleration units
m/s^2
uniform acceleration
constant acceleration
constant acceleration formula
v^2 - u^2 = 2 x acceleration x distance
what does the gradient on a distance time graph show you
the gradient at any point gives the speed of the object
what does the flat on a distance time graph show you
that the object has stopped
what does the curve on a distance time graph show you
that the object is accelerating
the curve getting steeper means that it is speeding up
a levelling off curve means that it is slowing down
how to calculate speed from distance time graph
draw tangent to the line
change in y or change in distance / change in x or change in time