Answer:
Explained
Explanation:
i)Two spheres hanging from nylon threads attract each other because either the two spheres are charged with opposite sign or only one of the spheres is charge so the other would be charge by induction of the charged sphere and hence attract each other.
ii)However, when they are touched the charges will be rearranged among the two sphere such that the two sphere have exact same magnitude and sign of charge and now they will repel each other or the magnitude of charges on the two spheres become zero and they neither attract or repel each other.
Answer:
The answer is: c. It does not move
Explanation:
Because the gravitational force is characterized by being an internal force within the Earth-particle system, in this case, the object of mass M. And since in this system there is no external force in the system, it can be concluded that the center of mass of the system will not move.
Answer:
part a : <em>The dry unit weight is 0.0616 </em>
<em />
part b : <em>The void ratio is 0.77</em>
part c : <em>Degree of Saturation is 0.43</em>
part d : <em>Additional water (in lb) needed to achieve 100% saturation in the soil sample is 0.72 lb</em>
Explanation:
Part a
Dry Unit Weight
The dry unit weight is given as

Here
is the dry unit weight which is to be calculated- γ is the bulk unit weight given as

- w is the moisture content in percentage, given as 12%
Substituting values

<em>The dry unit weight is 0.0616 </em>
<em />
Part b
Void Ratio
The void ratio is given as

Here
- e is the void ratio which is to be calculated
is the dry unit weight which is calculated in part a
is the water unit weight which is 62.4
or 0.04 
- G is the specific gravity which is given as 2.72
Substituting values

<em>The void ratio is 0.77</em>
Part c
Degree of Saturation
Degree of Saturation is given as

Here
- e is the void ratio which is calculated in part b
- G is the specific gravity which is given as 2.72
- w is the moisture content in percentage, given as 12% or 0.12 in fraction
Substituting values

<em>Degree of Saturation is 0.43</em>
Part d
Additional Water needed
For this firstly the zero air unit weight with 100% Saturation is calculated and the value is further manipulated accordingly. Zero air unit weight is given as

Here
is the zero air unit weight which is to be calculated
is the water unit weight which is 62.4
or 0.04 
- G is the specific gravity which is given as 2.72
- w is the moisture content in percentage, given as 12% or 0.12 in fraction

Now as the volume is known, the the overall weight is given as

As weight of initial bulk is already given as 4 lb so additional water required is 0.72 lb.
If Earth was twice as far from the sun, the force of gravity attracting the Earth to the sun would be only one-quarter as strong. The correct answer will be C.