When a part and a character attached together by rope and if the rope is short enough and the character is right on top of the part, the part or the character will fly with constant velocity.
I came across this strange physics behavior while building and such behavior is definitely not normal. This occurs 100% of the time, given you are using the right set up.
Steps To Reproduce
1.) Create a local script in StarterGui
2.) Insert this code
wait(0.1) local Platform = Instance.new("Part") Platform.Size = Vector3.new(6,1,6) Platform.Parent = game.Workspace local PlatformAttachment = Instance.new("Attachment") PlatformAttachment.Parent = Platform local Rope = Instance.new("RopeConstraint") Rope.Length = 2.1 Rope.Parent = Platform Rope.Attachment0 = PlatformAttachment Rope.Attachment1 = game.Players.LocalPlayer.Character.LowerTorso.WaistCenterAttachment