Physics Flashcards
Distance
A measurement of how far apart objects are
Scalar quantity- has a size but not a direction
distance = average speed x time D= v x t
Gradient
Slope of a hill of a graph: gradient = rise
run
Speed
The rate of change of distance
Average speed=distance v=d
time t
d=s x t OR t= d
s
Final speed=initial speed+(average acceleration x time taken) v=u + at
Velocity
The rate of change of displacement
Average velocity=change in displacement
time
Acceleration
Rate of change in velocity
a=v-u
t
Inertia
The tendency of an object to resist changes in its motion
Newtons 1st law of motion
An object at rest will remain this way unless it is acted upon by an unbalanced force; an object that is moving will continue to move in the same manner unless acted upon by an unbalanced force
Newtons 2nd law of motion
An object will accelerate in the direction of an unbalanced force acting upon it such that : F= m x a
(Force=mass x acceleration)
Newtons 3rd law of motion
For every action, there is an equal and opposite reaction
Displacement
a straight line connecting the start and end points that is specified in terms of length and direction
Vector quantity- has both size and direction
Speed time graph
Area- distance travelled Gradient = acceleration Constant moving- shown by flat line Increasing speed- graph rising upwards Decreasing speed- graph falling downwards
Displacement time graph
^ displacement
-> time
Converting units
M/s (x 3.6) -> km/h
Km/h (/3.6) -> m/s
Time tickers
5 dots = 0.1 seconds
The ticker vibrates up and down 50 times every second.
Constant speed- dots are evenly spaced
Accelerating- space between dots increases
Decelerating- spacing between dots decreases
Distance time graph
Steep line- fast
Straight horizontal line- not moving
Lower sloped line- slow
Acceleration due to gravity
9.8 m/s^2 Friction between air and a moving object will slow down large rates of acceleration (air resistance) Final velocity (terminal velocity)
Human tolerance of g-forces
Depend on: how big the forces are, how long they last, the direction in which they act and the part of the body they affect.
Can be dangerous in the vertical drop as blood flow to the brain can be disrupted and cause loss of consciousness or death.
Force and acceleration calculations according to newtons law
F= m x a
m= F
a
a=F
m
