Motion Flashcards
Is speed a vector or a scalar?
Speed is a scalar quantity: size only (magnitude)
Is velocity a vector or a scalar?
Velocity is a vector quantity: size (magnitude) and direction
e.g. +10m/s = velocity of 10m/s to the right (due east)
-10m/s = velocity of 10m/s to the left (due west)
Is acceleration is vector or a scalar?
Acceleration is a vector quantity: magnitude and direction.
Velocity
Speed in a given direction
What does the distance-time graph for an object at a constant speed look like?
A straight line that slopes upwards.
What does the gradient on a distance-time graph represent?
Speed
Speed in m/s =
Distance travelled in m
_____________________
Time taken in s
Displacement
Distance in a certain direction.
Vector
A physical quantity that has a direction and a magnitude.
Scalars
A physical quantity that has a magnitude only and not a direction.
Examples of Scalars
Speed
Distance
Time
Mass
Energy
Power
Examples of Vectors
Force
Momentum
Weight
Gravitational Field Strength
Acceleration
Velocity
Acceleration
An objects change of velocity per second.
Acceleration m/s(2) =
Change in velocity m/s
_____________________
Time taken s
What does the gradient of the line on a velocity-time graph represent?
Acceleration
What does the distance-time graph of a stationary object look like?
A horizontal line
What does the area underneath a velocity/time graph represent?
Distance travelled.
How to find the gradient of a distance-time graph
(speed)
Draw a triangle under the line.
gradient of the line= height of the triangle/ base of the triangle (rise/run)
Practical for measuring distance:
> Measure out a distance
Station someone at either end.
1st student gives a signal as the vehicle passes
Second student starts timing.
Stop timing when vehicle passes.
Calculate speed as distance/time
How to find the gradient of a velocity -time graph
(acceleration)
The height of the triangle under the line/ base of the triangle under the line
(acceleration = change of velocity/ time taken)
(rise/run)
How force changes an objects motion
A force applied to an object may cause it to accelerate, decelerate or come to complete rest
Force formula
Force = Mass x acceleration
F=ma
Circular motion
With circular motion the acceleration is toward the center of the circle
Size of the perpendicular force is affected by:
*Mass of object
*Speed of object
*Radius of the circle (Smaller the radius greater the force)
Acceleration V-U meaning
V>Final velocity
U>Initial velocity
In a velocity-time graph area beneath the graph is _______
distance
