Issue with VelocityForce

Hi! So, I have made a game where the player spawns as a ship. I’ve added a VelocityForce that is able to be controlled as the throttle of the ship. However it seems that I am encountering a sudden boost of acceleration when it reaches a certain point:

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Here, I have made a script where it adds 1000 force to the VelocityForce every 0.5 seconds and printed the magnitude of the character’s HumanoidRootPart. As you can see in the red box, the magnitude is no longer linear to the magnitude in the past.

Is there any way to solve this issue?
In addition, is there also a way for me to increase the speed of the boat into a line similar to y=ax^(1/2)?

I’ve found an issue with this: When the model has a part named HumanoidRootPart, it will suffer this kind of non-linear increase of velocity. Perhaps anyone knows anything about this?

Try to use RunService instead of velocity and add acceleration.
And that’s all about it.