Answer:
a) 1/4 what it is now
Explanation:
As we know that force of gravitation between two planets at some distance "r" from each other is given as

now since we know that if the distance between Earth and Sun is changed
So the force of gravity will be given as

now we know that the distance between sun and earth is changed to twice the initial distance between them
so we have

so new gravitational force between sun and earth is given as


Plants get it from the roots or leaves
animals get it by breathing
An electric force exists between the following:
-Two negative objects
-Two positive objects
-A negative object and a positive object
Answer:
Explanation:
Work in pumping water from the tank is given as
W = ∫ y dF. From a to b
Where dF is the differential weight of the thin layer of liquid in the tank, y is the height of the differential layer
a is the lower limit of the height
b is the upper limit of the height.
We know that, .
F = ρVg
Where F is the weight
ρ is the density of water
V is the volume of water in tank
g is the acceleration due to gravity
Then,
dF = ρg ( Ady)
We know that the density and the acceleration due to gravity is constant, also the base area of the tank is constant, only the height that changes.
Then,
ρg = 62.4 lbs/ft³
Area = L×B = 3 × 9 = 27ft²
dF = ρg ( Ady)
dF = 1684.8dy
The height reduces from 12ft to 0ft
Then,
W = ∫ y dF. From a to b
W = ∫ 1684.8y dy From 0 to 12
W = 1684.8y²/2 from 0 to 12
W = 842.4 [y²] from y = 0 to y = 12
W = 842.4 (12²-0²)
W = 121,305.6 lb-ft
Answer: The correct answers are (A) and (C).
Explanation:
The expression from electrostatic force is as follows;

Here, F is the electrostatic force, k is constant, r is the distance between the charges and
are the charges.
The electrostatic force follows inverse square law. It is inversely proportional to the square of the distance between the charges. It is directly proportional to the product of the charges.
Like charges repel each other. There is a force of electrostatic repulsion between the like charges. Unlike charges attract each other. There is a force of electrostatic attraction between unlike charges.
The charges are induced on the neutral object when it is placed nearby the charged object without actually touching it.
Therefore, the true statements from the given options are as follows;
Like charges repel.
Unlike charges attract.