Question

Objects A and B are at the origin. If object A moves to `(3 ,-7 )` and object B moves to `(2 ,9 )` over `2 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 `= <-1/2, 8>ms^-1`

Explanation:

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

The absolute velocity of `B` is `v_B=1/2 <2,9> = <1,9/2>`

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

`v_(B//A) =v_B-v_A= <1,9/2> - <3/2,-7/2>`

`= <(1-3/2), (9/2+7/2)>`

`= <-1/2, 8>`