Answer:
a. Vf = 39.24 [m/s]
b. Vf = 31.24 [m/s]
c. Vf = 47.24 [m/s].
Explanation:
To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (when the rock is dropped)
g = gravitational acceleration = 9.81 [m/s²]
t = time = 4 [s]
a.
![v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D0%2B9.81%2A4%5C%5Cv_%7Bf%7D%3D%2039.24%20%5Bm%2Fs%5D)
b.
In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.
![v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D8-%289.81%2A4%29%5C%5Cv_%7Bf%7D%3D-31.24%5Bm%2Fs%5D)
The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.
c.
![v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%3D8%2B%289.81%2A4%29%5C%5Cv_%7Bf%7D%3D47.24%5Bm%2Fs%5D)
Answer:
i) C decreases
ii) Q remains constant
iii) E remains constant
iv) ΔV increases
Explanation:
i)
We know, capacitance is given by:
<em>In this case as the distance between the plates increases the capacitance decreases while area and permittivity of free space remains constant.</em>
ii)
As the amount of charge has nothing to do with the plate separation in case of an open circuit hence the charge Q remains constant.
iii)
Electric field between the plates is given as:
where:
charge density, 
<em>As we know that distance of plate separation cannot affect area of the plate. Charge Q and permittivity are also not affected by it, so E remains constant.</em>
iv)
- From the basic definition of voltage we know that it is the work done per unit charge to move it through a distance.
- Here we increase the distance so the work done per unit charge increases.
Answer:
In chemistry and physics, a valence electron is an outer shell electron with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
Explanation:
If the object sinks, then it must be heavier than the weight of the water
it displaces ... heavier than the buoyant force acting on it.
If the buoyant force were equal or greater than the object's weight, then
the object would rise to the surface in water.
