After the jumper goes faster than terminal velocity, the air resistance force is greater than the weight so that the acceleration is in the positive direction.

What is terminal velocity? Well, when an object is falling in the atmosphere there are two forces that mostly govern the object’s motion. Here is a diagram.

At t 2, the angular velocity is zero, with a non-zero (positive) angular acceleration. At that time, the direction of rotation for BC is changing from CW to CCW. In summary, you should never assume ...

Learn about and revise terminal velocity, Newton's Laws and braking forces with GCSE Bitesize Combined Science.

Wide binary stars with separation greater than about 2000 astronomical units are interesting natural laboratories that allow a direct probe of gravity at low acceleration weaker than about 1 ...

Consider this plot of cam dynamics: Cam design requires you to keep sight of the follower displacement and the first, second, and third derivatives: velocity, acceleration, and jerk.