Question

Objects A and B are at the origin. If object A moves to `(-2 ,2 )` and object B moves to `(7 ,9 )` 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 `=<3, 7/3 > ms^-1`

Explanation:

The absolute velocity of `A` is

`v_A= 1/3 <-2, 2 > = <-2/3, 2/3> ms^-1`

The absolute velocity of `B` is

`v_B= 1/3 <7, 9> = <7/3, 3> ms^-1`

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

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

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

`= <3, 7/3 > ms^-1`