Using LinearVelocity

hey guys, i have been trying to figure out some stuff with the linearvelocity, is there any way that i could use it for sine wave? so like.
my situation is that i have a wall running, but i want it to be realistic and its only going like linear.

what i have done is:

if iCount < 12 then
	wallrunForce.VectorVelocity = Vector3.new(0,15,0) + velocity
elseif iCount > 12 then
	wallrunForce.VectorVelocity = Vector3.new(0,-15,0) + velocity
end

https://gyazo.com/e5b11221516e3edfa17848324ccdc838?token=96d81378f1a4ddf19194153fa8780929