How would I go about transferring momentum from the player to a thrown object?

I am interested in making throwable objects for my game but am running into an issue where if the player is moving forward quickly, they can run into their own projectile. While I am sure there is an easy way around this, I think it would make more sense to just add the players velocity to the projectile so that faster moving players can launch the projectile further. I think the easiest way to do this would be to just have an interface in the projectiles construction script that gets the owners velocity however I am having a very hard time with the actual math to make this work. Would anyone know what vectors I would need to get from the player/add to the projectile to make this work? The main issue I am having are that I don’t know how to give the projectile itself a base velocity (i.e. I can’t figure out how to make it go directly forward with reference to the player).