Answer:
7572 m/s
Explanation:
The force between two masses separated by a distance r is given as:

Where F is the attractive force between 2 masses, m1 and m2, r is the distance between the centres of the masses and G is the universal gravitation constant, which is 
The mass of the earth (
) is far greater than the mass of the sputnik (
). Therefore
. The mass of the sputnik is neglected, therefore:

But F is actually centripetal acceleration, a = v²/r

Answer:
1) A downward force of magnitude 5 N is exerted on the book by the force of of gravity
2) An upward force of magnitude 5 N is exerted on the book by the table
Explanation:
First of all, any object near the Earth's surface experiences the forces of gravity, which is also called weight of the object. This force always acts downward.
For the book in the problem, the magnitude of the weight is 5 N.
We also know that the book is at rest: this means that the net force acting on it is zero, and there must be another force balancing the weight, in order to give a zero net force. This other force is the reaction force exerted by the table on the book: the magnitude of this force must be equal to the force of gravity (so, 5 N) and its direction is opposite to the weight, therefore upward.
Answer:
(D) the sphere
Explanation:
The bodies given are Disk and Solid sphere (uniform sphere)
Moment of inertia of the bodies are
I(disk) =
I(sphere) = 
Since the moment of inertia of sphere is less than that of disk, therefore sphere will reach the bottom first.
Answer:
Drought
Explanation:
If you are asking about Number 2. then the answer would be lack of precipitation (rain).
Climate change didn't allow for cold air to meet the warm air to produce precipitation over the run off area of the lake.
Answer:
The distance of separation is decreased
Explanation:
From Cuolomb's law, we know that the strength of charge is inversely proportional to the distance of separation between the charges. To mean that increasing the distance let's say from 2m to 3 m would mean initial strength getting form 1/4 to 1/9 which is a decrease. The vice versa is true hence the force of repulsion can increase only when we decrease the distance of separation.