A) 
The total energy of the system is equal to the maximum elastic potential energy, that is achieved when the displacement is equal to the amplitude (x=A):
(1)
where k is the spring constant.
The total energy, which is conserved, at any other point of the motion is the sum of elastic potential energy and kinetic energy:
(2)
where x is the displacement, m the mass, and v the speed.
We want to know the displacement x at which the elastic potential energy is 1/3 of the kinetic energy:

Using (2) we can rewrite this as

And using (1), we find

Substituting
into the last equation, we find the value of x:

B) 
In this case, the kinetic energy is 1/10 of the total energy:

Since we have

we can write

And so we find:

Answer:

Explanation:
Given:
dimension of uniform plate, 
mass of plate, 
Now we find the moment of inertia about the center of mass of the rectangular plate is given as:

where:
length of the plate
breadth of the plate


We know that the center of mass of the rectangular plane is at its geometric center which is parallel to the desired axis XX' .
Now we find the distance between the center of mass and the corner:


Now using parallel axis theorem:



Answer:
Explanation:
Mob violence is never protected. Organizers are always careful about not letting things get out of hand. Not D
That remark sort of applies to C as well. Property destruction is never protected.
B is something assemblies are allowed to do. So B.
A falls into the same category as C and D. You may not like the fact that he/she is doing something illegal, but you can't take away their privacy.