Lecture 3 Kinematics Flashcards
What is displacement?
The change in an objects position from an initial location to a final location
Usually expressed in meters (m)
Is a vector quantity meaning requires magnitude and direction
To calculate, draw a straight line from initial position to final position
Displacement =…
Final position (pf) - initial position (pi)
What is velocity?
Rate of change of an objects displacement over a particular time interval
Usually expressed in (m/s)
Vector quantity meaning requires magnitude and direction
Velocity = displacement / time = pf - pi / tf - ti
Distance vs displacement
Distance is a scaler and reflects the total length travelled
Displacement is a vector and is the difference in position from the final position and the initial position
If an object moves in a straight line, displacement and distance are…
Equal
If an object does not move in a straight line: distance and displacement will…
Not be equal
Displacement is always … to distance
Less than or equal to
What is speed?
A scaler quantity calculated as the distance travelled over time or rate of distance travelled over time
Speed has no reference to the direction that an object or person is travelling
Speed =…
Distance / time
What is average velocity?
Reflects the average change in displacement over a time interval
What is instantaneous velocity?
Reflects the rate of change of displacement at a particular instant in time
How can instantaneous velocity be calculated?
Using visual inspection or the central difference method
What happens to displacement when we increase velocity and keep time constant?
Displacement increases
What happens to displacement when we increase time and keep velocity constant?
Displacement increases
Can we calculate displacement if velocity and time are known?
Yes, multiply velocity by time
