The answer is reflection.
Answer:
v = 14 m/s
Explanation:
given,
radius of dip = 40 m
The passengers in a roller coaster car feel 50% heavier than their true weight.
Apparent weight



When the car is at the bottom, the weight will be acting downwards and the centripetal force will also be acting downward where as Normal force which is apparent weight will be acting in upward direction.
now,





v = 14 m/s
Gravity, friction, and air resistance are some examples.
This is what wiki says hope it helps
A displacement is a vector whose length is the shortest distance from the initial to the final position of a point P.[1] It quantifies both the distance and direction of an imaginary motion along a straight line from the initial position to the final position of the point.
A displacement may be also described as a 'relative position': the final position of a point (Sf) relative to its initial position (Si), and a displacement vector can be mathematically defined as the difference between the final and initial position vectors: