Second, calculating the motion of an object with air resistance is really difficult, because the drag force increases with velocity—it's non-constant.

When an object falls it can reach terminal velocity. Find out more with BBC Bitesize. For students between the ages of 11 and 14.

Don't fall into the common trap of thinking that a constant force makes an object move at a constant speed. This just isn't true. Force pushing in the opposite direction as the velocity of the object.

Using and interpreting graphs - OCR Speed-time and velocity-time graphs. In real-life contexts, the intercept, ... the object is travelling at a constant velocity of 8 m/s.