Question

Objects A and B are at the origin. If object A moves to `(5 ,-8 )` and object B moves to `(-4 ,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 of `B` with respect to `A` is `= < -3, 10/3> ms^-1`

Explanation:

The absolute velocity of `A` is `v_A=1/3 <5,-8> = < 5/3,-8/3> ms^-1`

The absolute velocity of `B` is `v_B=1/3 <-4,2> = < -4/3,2/3> ms^-1`

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

`v_(B//A)=v_B-v_A= < -4/3,2/3> - < 5/3,-8/3>`

`= <-4/3-5/3, 2/3+8/3 >`

`= < -3, 10/3> ms^-1`