Unit 1.2 - Kinematics Flashcards
Displacement
The shortest distance from A to B along with direction
(The vector that corresponds to that distance)
Displacement unit
m
What’s the difference between displacement and distance?
Displacement has a positive and a negative, meaning they can cancel out
(Displacement is a vector)
Average speed
Total distance travelled divided by the total time taken
Instantaneous
In an instant
Instantaneous speed
The rate of change of distance
Speed unit
ms-1
Instantaneous speed on a graph
Gradient of the tangent of the distance-time graph at a given point
Average velocity
Total displacement travelled divided by the total time taken
Instantaneous velocity
The rate of change of displacement
Velocity unit
ms-1
Velocity on a graph
Gradient of the tangent on a displacement - time graph at a given point
Average acceleration
The change in velocity divided by the time taken for the change
Change in velocity
V - u
Instantaneous acceleration
The rate of change of velocity
Velocity unit
ms-2
Acceleration on a graph
Gradient of the tangent of the velocity-time graph at a given point
Symbol for displacement
x
How do we know if displacement is directly proportional to time on a graph?
Straight line through the origin
What does it mean if we have a straight one through the origin on a displacement-time graph?
Displacement is directly proportional to time
= the cars are moving at constant acceleration
When would we know if the cars are moving at constant acceleration on a displacement-time graph?
With a straight line through the origin that shows displacement is directly proportional to time
If a line is steeper than another on a displacement-time graph, what does it mean?
It has a higher constant velocity
What do we need to remember about the axes of the displacement-time graph?
As it’s a vector, it has both a positive and a negative
What does a flat line on a displacement-time graph tell us?
Gradient = 0
Velocity = 0
Body is stationary