Module 3 - Forces and motion (Kinematics) Flashcards
Motion: Kinematics
What is meant by the term displacement
The distance travelled in a given direction
What is meant by the term instantaneous speed
A measure of the speed of an object over a very short interval of time.
How is instantaneous speed calculated from a distance time graph
- A tangent is drawn about the instant of time
- The gradient of the tangent is determined which represents the instantaneous speed
What is meant by the term average speed
A measure of the total distance travelled over a given time.
How is the average speed of an object determined from a distance time graph
The gradient of the straight line or between the initial and the final point is calculated to determine the average speed
What is a limiatation of finding the average speed in a practical sense and give an example
It does not represent the variation in speed of the object.
(E.G.) A cas average speed may not exceed the average speed limit evemn if it exceeds the limit in one part of the journey.
What is meant by the term acceleration
The rate of change if velocity
What is the equation that links to the definition of acceleration
a = v-u/t
What is meant by the term velocity
The displacement travelled by an object in a given time
What is the equation that links to the definition of velocity
v = s / t
What is the unit of velocity
ms -1
What is the unit of acceleration
ms -2
What does the gradient of an s/t graph represent
The velocity
What does an negative displacement represent on an s/t graph
The motion of the object is in the opposite direction
What does the gradient of a v/t graph represent
The acceleration
