Question

Objects A and B are at the origin. If object A moves to `(5 ,-3 )` and object B moves to `(-7 ,2 )` over `3 s`, what is the relative velocity of object B from the perspective of object A? Assume that all units are denominated in meters.

Answer 1

The relative velocity is `= <-4, 5/3> ms^-1`

Explanation:

The absolute velocity of `A` is `v_A=1/3 <5,-3> = <5/3, -1>`

The absolute velocity of `B` is `v_B=1/3 <-7,2> = <-7/3, 2/3>`

The relative velocity of `B` with respect to `A` is

`v_(B//A)=v_B- v_A=<-7/3, 2/3> - <5/3, -1>`

`= <-7/3-5/3, 2/3+1>`

`= <-4, 5/3> ms^-1`