The document discusses true velocity and relative velocity. It defines true velocity as the velocity of a moving object relative to the earth. It explains that the apparent path of an object depends on the observer's frame of reference. It provides examples of how to calculate relative velocity between two moving objects by using an equation and drawing a velocity diagram.

1. Relative Velocity
Grade 10
Additional Mathematics

2. TRUE VELOCITY
A C
2 m s-1 20 km h-1
A girl (G) jogs along a straight road at a A cyclist (C) travels at a speed of
speed of 2 ms-1 due EAST 20 kmh-1 due WEST
VG = 20 ms-1 VC = 20 kmh-1
The velocity of a moving object P relative to the earth is
known as a TRUE VELOCITY and denoted by VP

3. Relative Motion of Two Moving Objects
APPARENT (RELATIVE) PATH

4. RELATIVE VELOCITY
P Q OBSERVER
3 ms-1 2 ms-1
To the man Q, the girl P appears to move at a
speed of 1 ms-1 towards Q. Relative to Q
(observer), P is moving at a speed of 1 ms-1
due east as shown
Relative Velocity Equation
Velocity Diagram

5. RELATIVE VELOCITY
P OBSERVER Q
3 ms-1 2 ms-1
To the the girl P , the man Q, appears to move
at a speed of 1 ms-1 towards P. Relative to P
(observer), Q is moving at a speed of 1 ms-1
due west as shown
Relative Velocity Equation
Velocity Diagram

6. What is the velocity of A relative to B?
1. Write down the relative velocity equation
2. Draw the velocity diagram

7. What is the velocity of A relative to B?
1. Write down the relative velocity equation
2. Draw the velocity diagram
1.5 units
7.5 units