A ITS RIGHT I GOT 100 ON MY UNIT TEST
There are two types of equilibrium in mechanics.One is called static equilibrium and the other one is called dynamic equilibrium. In both the cases of mechanical equilibrium,the net force acting on the particle is zero.
A body is said to be in dynamic equilibrium if the net force acting on a moving body is zero.There will be no acceleration of the body.The body will continue its uniform motion without change in its direction and speed.
The body is said to be in static equilibrium if the net force acting on a body at rest is zero.As the net force is zero,the body will not undergo motion. It is due to the inertia of the body.
The two equilibrium are the direct consequences of Newton's first law which tells that a body will continue to be at state of rest or uniform motion along a straight line unless and until it is compelled by some external unbalanced force.Hence as long as net force on the body is zero,the body at rest will satisfy static equilibrium.
Out of the four options given in the question only third option is right which tells that a book that has no net force acting on it and sitting on a table is under static equilibrium. If the net force is not zero,the body can not be under static equilibrium.The book resting on a table imparts a force equal to its weight on the table and table in turn gives the normal reaction in vertically upward direction.The gravity pulls the book in vertically downward direction with a force equal to its weigh.Hence the net force is zero.So the table will be at rest.
If the net force is not zero,the body can not be under static equilibrium.
Hence option 3 is right.
To solve this problem it is necessary to apply the concepts related to acceleration due to gravity, as well as Newton's second law that describes the weight based on its mass and the acceleration of the celestial body on which it depends.
In other words the acceleration can be described as
Where
G = Gravitational Universal Constant
M = Mass of Earth
r = Radius of Earth
This equation can be differentiated with respect to the radius of change, that is
At the same time since Newton's second law we know that:
Where,
m = mass
a =Acceleration
From the previous value given for acceleration we have to
Finally to find the change in weight it is necessary to differentiate the Force with respect to the acceleration, then:
But we know that the total weight (F_W) is equivalent to 600N, and that the change during each mile in kilometers is 1.6km or 1600m therefore:
Therefore there is a weight loss of 0.3N every kilometer.
I think that the oceanic water particles mainly move in circles greater in the oceans surface because of how big the waves can be and how wind and air impact the motion. The water particles move more on the surface because of the other factors that impact it such as people, wind, air, etc...
