The Velocity of a part describes how its
/BasePart/Position is presently changing. The unit of this property is studs per second. For reference, the default Roblox character moves at 16 studs per second via
/Humanoid/WalkSpeed. The acceleration due to gravity is found in
/Workspace/Gravity (by default, -196.2 studs per second).
Setting the Velocity of an part that is
/BasePart/Anchored will cause it to act like a conveyor belt. Any object that touches the part will begin to move in accordance with the Velocity.
/BodyMover objects will apply forces and thus change the Velocity of a part over time. The simplest of these is a
/BodyForce which can be used to counteract the acceleration due to gravity on a single part (set the +Y axis of the
/BodyForce/Force to the product of the mass (
/BasePart/GetMass) and the gravity constant).
This code sample fires a part from one position toward another. It calculates the velocity needed to reach the destination in time, and applies an anti-gravity effect using a BodyForce. In addition, it adds a Trail to better visualize the path of the projectile as it arcs through the air.