Displacement, Velocity, and Acceleration

A measure of how far an object travels

Distance

A quantity that has magnitude only

Scalar

Distance is a scalar/vector quantity

Scalar

What is the distance covered in the race?

300 m

A measure of how far something is from its starting position, along with its direction

Displacement

The change in position

Displacement

A quantity that has both magnitude and direction

Vector

Displacement is a scalar/vector quantity

Vector

Describe the displacement of a runner after completing the race

100m to the right

If a runner ran one complete loop on the track, what is his displacement?

0

Why is distance a scalar quantity?

It describes how far an object has travelled overall, but not the direction it has travelled in

Why is displacement a vector quantity?

It describes how far an object is from where it started and in what direction

The distance an object travels every second

Speed

Speed is a scalar/vector quantity

Scalar

Speed has magnitude only / direction only / both magnitude and direction

Magnitude only

The average speed of an object is given by the equation:

Average speed = total distance / time taken

The SI units for speed are:

m/s

Can speed be measured in alternative units, instead of the SI units?

Yes

When is speed measured in alternative units instead of SI units?

When it is more appropriate for the situation

Is the velocity of a moving object similar to its speed?

Yes

Does velocity describe direction?

Yes

The rate of change of displacement

Velocity

Unit of velocity:

m/s

Velocity is a scalar/vector quantity

Vector

Why is velocity a vector quantity?

It describes both magnitude and direction

The speed in a given direction

Velocity

How to calculate average velocity of an object?

Total displacement (m) over total time taken (s)

If the initial velocity u and final velocity v are known, the average velocity can be calculated using:

(u+v)/2

Is average velocity average speed in a given direction?

No

Why is average displacement not average speed in a given direction?

Speed uses distance while velocity uses displacement, and the magnitudes of speed and velocity can be very different for the same motion

The rate of change of velocity:

Acceleration

Acceleration is a scalar/vector quantity

Vector

Acceleration is measured in:

m/s²

Acceleration describes:

How much an object's velocity changes every second

How to calculate average acceleration of an object?

Change in velocity (m/s) over total time taken (s)

The difference between the initial and final velocity

Change in velocity