Objects A and B are at the origin. If object A moves to $(- 7, 2)$ $(-7 ,2 )$ and object B moves to $(- 5, - 6)$ $(-5 ,-6 )$ over $2 s$ $2 s$ , what is the relative velocity of object B from the perspective of object A?

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Answer 1 · 2018-01-20T06:52:24

The relative velocity is $= < 1, - 4 > m s^{- 1}$ $= < 1, -4> ms^-1$

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The time is $t = 2 s$ $t=2s$

The absolute velocity of $A$ $A$ is $v_{A} = \frac{1}{2} \cdot < - 7, 2 > = < - \frac{7}{2}, 1 >$ $v_A=1/2* <-7, 2> = <-7/2, 1>$

The absolute velocity of $B$ $B$ is $v_{B} = \frac{1}{2} \cdot < - 5, - 6 > = < - \frac{5}{2}, - 3 >$ $v_B=1/2* <-5, -6> = <-5/2, -3>$

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

$v_{B / A} = v_{B} - v_{A}$ $v_(B//A)=v_B-v_A$

$= < - \frac{5}{2}, - 3 > - < - \frac{7}{2}, 1 >$ $= <-5/2, -3> - <-7/2, 1>$

$= < - \frac{5}{2} - (- \frac{7}{2}), - 3 - (1) >$ $= <-5/2-(-7/2), -3-(1) >$

$= < 1, - 4 > m s^{- 1}$ $= < 1, -4> ms^-1$

Objects A and B are at the origin. If object A moves to (-7 ,2 )(−7,2)(-7 ,2 ) and object B moves to (-5 ,-6 )(−5,−6)(-5 ,-6 ) over 2 s2s2 s, what is the relative velocity of object B from the perspective of object A?