Why is the player going the wrong direction with bodyvelocity?

v.Velocity = Vector3.new(-3,0,0)
v.Velocity = char.HumanoidRootPart.CFrame.lookVector *-8

how I do make my bodyvelocity move back cause I try that it move back the opposite direction but I want it just to move back by the players torso so I try lookVector it moves back but it doesn't move the player on his/her side...