Answer:
Explanation:
The stunt will likely sustain serious injury in case of concrete blocks because the average force acting on the person will be more because concrete blocks do not squeeze to provide more time for the force to act on the body instead it acts for a small amount of interval.

As impulse is constant so time requires to act force on the body is more as compared to concrete block and thus average force in mattress case is less.
Answer:
I think false I don't know if I right but I hoped this help
<span>Valence electrons are electrons in the outermost shell available for bonding</span>
A "folk" remedy is something you choose to eat, take, or do,
in order to correct some health issue, because your friend,
your grandmother, your religion, your shaman, your astrologer,
or your medicine man says that it's the right thing to do.
It may or may not be effective, and it may or may not even be
safe. What distinguishes it from mainstream medicine is that
its practices are based on hearsay, and have not been subjected
to scientific methods of investigation and evaluation.
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Answer: Please see below as the answer is self-explanatory.
Explanation:
The Newton's 3rd law, in simple words, explains, that for any force exerted on an object by another one, there exists a reaction from the object acted upon, which consists in another force, that is of equal value that the one is being exerted on it, but in the opposite direction, and is acting on the the other object.
So, Newton's 3rd Law says that for any pair of objects interacting, there is a pair of forces, equal and opposite, that each of them exerts on the other.
It is very important to understand, that in any free body diagram, it must be showed only one of these forces, the reaction that the other object is exerting on the object for which we are drawing the FBD, not the two forces, as the another one is external to the other object.
One example for this is the normal force, the gravity force, etc.