What does positive G-force do to the body?

Positive G-force primarily affects the body by creating a force that pulls individuals into their seats. When rapid acceleration occurs, such as during a sudden increase in speed or changes in direction, the body experiences an increase in gravitational force, which effectively multiplies the weight felt by the body. This force acts in the direction opposite to that of acceleration, leading to a sensation of being pushed down into the seat.

This phenomenon is particularly noticeable in situations such as aircraft maneuvers or amusement park rides, where the effects of G-forces can be experienced acutely. While the other options describe possible effects of G-forces in varying contexts, they do not specifically represent the primary impact of positive G-force on the human body. For instance, increased blood flow to the head can occur under certain conditions of negative G-force, and disorientation can be a result of high G-forces but is not the direct consequence of positive G-force alone.