Physics Test Flashcards
We often use the term
Average speed
The formula to calculate average speed is:
Distance traveled divided by time taken
The units of speed are
km/h & m/s
To convert between km/h and m/s you
To convert from m/s to km/h you x 3.6 and to convert km/h to m/s you divide by 3.6
The formula for distance is
Speed x time
The formula for time is:
Distance divided by speed
Velocity must
Take into account direction
Velocity is
Speed with direction
A distance time graph
Shows how far an object travels as time progresses
A horizontal line
Indicates that the motion has stopped
A line with a steep slope indicates
That the object covers a greater distance and is moving faster than an object with a gentle slope
The slope is also known as:
The gradient
A speed time graph shows
How an objects speed changes over time
On a speed - time graph if the line is horizontal
It indicates constant speed
On a speed tine graph the line rising up
Indicates increasing speed ( acceleration )
On a speed time graph the line falling down
Indicates decreasing speed (negative acceleration/ deceleration)
Speed is the measure…
Of how quickly something moves
The rate at which speed changes is called
Acceleration
A positive acceleration indicates that
Something is speeding up
A negative acceleration indicates that
Something is slowing down
Acceleration has units of
m/s/s or km/hr/s
The formula for acceleration is
Is vf - vi divided by t
The formula for vf (final speed) is
a times t plus vi I
The formula for vi ( initial speed) is
a times t takeaway vf
Vi is
Initial speed
Vf is
Final speed
A falling object
Accelerates towards earth because of the force of gravity
As objects fall to the earth they
Speed up
The speed of a falling object
Increases by 9.8m/s every second
Newtons first law of motion states:
An object at rest will remain at rest unless acted upon by a force, and that an object that is moving will continue to move at the same speed unless stated upon by an unbalanced force
Iteria is
An objects tendency to maintain its state of motion i.e: if it is at rest it will stay at rest
Newtons second law of motion states:
An object will accelerate in the direction of an unbalanced force acting upon it. The size of the acceleration depends on the mass of the object and the size of the force acting upon it
The formula for force is:
M x a ( mass x acceleration)
The formula for mass is:
Force divided by mass
The formula for acceleration is:
F divided by m (force divided by mass)
Newtons third law states
For every action there is an equal and opposite reaction force
