His law states that every particle is attracted to every other particle in the universe using a force that is proportional to the product of their masses <span />
Answer:
<em>The person needs to apply 25 N to balance the seesaw</em>
Explanation:
<u>Moment</u>
The moment of a force is a measure of its tendency to cause a body to rotate about a specific point or axis.
The moment M of a force F located at a distance x from the axis of rotation is calculated as follows:
M = F.x
The image shows a moment of M=100 N.m is needed to be applied to balance the seesaw. It can also be noted that the distance to the pivot is x=4 m
To calculate the force needed to balance the seesaw, we solve for F:


F = 25 N
The person needs to apply 25 N to balance the seesaw
I would say that the answer would be MASS.
Early hypotheses were not based on observations.
Early hypotheses were not tested by experimentation.
Early hypotheses were formed from scientific questions.
Early hypotheses were influenced by creative thinking
Thank you for your question, what you say is true, the gravitational force exerted by the Earth on the Moon has to be equal to the centripetal force.
An interesting application of this principle is that it allows you to determine a relation between the period of an orbit and its size. Let us assume for simplicity the Moon's orbit as circular (it is not, but this is a good approximation for our purposes).
The gravitational acceleration that the Moon experience due to the gravitational attraction from the Earth is given by:
ag=G(MEarth+MMoon)/r2
Where G is the gravitational constant, M stands for mass, and r is the radius of the orbit. The centripetal acceleration is given by:
acentr=(4 pi2 r)/T2
Where T is the period. Since the two accelerations have to be equal, we obtain:
(4 pi2 r) /T2=G(MEarth+MMoon)/r2
Which implies:
r3/T2=G(MEarth+MMoon)/4 pi2=const.
This is the so-called third Kepler law, that states that the cube of the radius of the orbit is proportional to the square of the period.
This has interesting applications. In the Solar System, for example, if you know the period and the radius of one planet orbit, by knowing another planet's period you can determine its orbit radius. I hope that this answers your question.