Electrostatic forces to simulate or counteract real forces.

Outside forces such as momentum and gravity can be simulated by the electrostatic force. A human or other subject would be electrically charged, then the vessel they're inside would have its walls charged so that one side is positive and one is negative. The charged subject would then feel a force depending on how much they were charged and how much the walls were charged.

The walls can be charged to counteract the impact of momentum, making higher acceleration possible without injury or discomfort. The walls can also be charged to simulate forces for use in VR experiences, for example a rollercoaster can be made to feel real but be completely stationary.