Answer:
Since strong nuclear forces involve only nuclear particles (not electrons, bonds, etc) items 3 and 4 are eliminated.
Again item 2 refers to bonds between atoms and is eliminated.
This leaves only item 1.
Nuclear forces are very short range forces between components of the nucleus.
Weak nuclear forces are trillions of times smaller than strong forces.
Gravitational forces are much much smaller than the weak nuclear force.
Answer:
800 N
Explanation:
By Newton's third law which states that for every action, there is an equal and opposite reaction.
So, as the earth attracts the person towards its center, the person attracts the earth towards itself with the same magnitude of force but in the opposite direction.
Since the person is attracted towards the center of the earth by an 800 N gravitational force, the the earth is attracted toward the person with an 800 N reaction force.
If you are pushing the coin across the table at a constant rate, the friction of the table and the horizontal force of your hand pushing are equal, and the coin itself moves at a constant rate. If you push a coin and let it go, there is no horizontal force keeping the coin going. Friction slows the coin to a stop. In both cases, the gravitational downward pull of Earth is equally but oppositely resisted by the upward push of table on the coin.
The AREA of the shaded region is the moving object's displacement.