Relative velocity is used to designate the aircraft traveling in the wind or boats sailing through the water, etc. The velocity is calculated within the object as per the observer using the relative velocity formula in relativity. It can be computed with the help of an intermediate reference frame. Simply, this can be the vector sum of the velocities. The formula to find relative velocity is expressed as:
vAB = vA – vB.
where,
VAB = the velocity in reference to A and B,
VB = the velocity with reference to B
VA = is the velocity in reference to A
Solved Examples Using Dimensional Formula of Relative Velocity
Example:
A bus with a speed of 90 m/s with respect to the ground in the west direction. An onlooker is moving at a speed of -25m/s with respect to the train in the west direction. Find out the speed of the onlooker with respect to the ground?
Solution:
From the problem, it is familiar that,
VAB (Velocity of man in reference to train) = -25m/s
VB (Velocity of train in reference to ground) = 90 m/s
VA (Velocity of an onlooker in reference to ground) =?
Relative Velocity Formula is,
vAB = vA – vB.
vAB→ = -25 – 90 = -115m/s
Thus, VAC→ = -115m/s