B. the reason we must wear seat belts
Answer:

Explanation:
As we know that we board in the car of ferris wheel at the bottom position
So we will have
final height of the car at angular displacement given as


here we know that


so we have


Series Circuit
A series circuit there is only one path for the electrons to flow (see image of series circuit). The main disadvantage of a series circuit is that if there is a break in the circuit the entire circuit is open and no current will flow. An example of a series would the the lights on many inexpensive Christmas trees. If one light goes out all of them will.
Parallel Circuit
In a parallel circuit the different parts of the electric circuit are on several different branches. There are several different paths that electrons can flow. If there is a break in one branch of the circuit electrons can still flow in other branches (see image of parallel circuit). Your home is wired in a parallel circuit so if one light bulb goes out the other will stay on.
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Answer: B
Explanation:
An unbalanced force (net force) acting on an object changes its speed and/or direction of motion. An unbalanced force is an unopposed force that causes a change in motion.
I'm not completely sure, but I believe the answer is B. Solid