Answer:
1. Torque → F. Study of forces
2. C.O.G → D. Point of action of weight.
3. Plumb line → A. Line of C.O.G
Answer:
Explained
Explanation:
A) The total energy of the system is defined by the energy at maximum amplitude, which we'll call A. At that point, the energy of the system is
E = 1/2×m×A^2;
since energy is conserved, this is also the total amount of energy that the system ever has.
So at x=1/2A,
the potential energy of the system is 1/8×m×A^2
which is one-fourth of the system's total energy. Therefore, the remaining three-fourths is kinetic.
B) (i) Doubling the maximum amplitude will quadruple the total energy:

(ii) Doubling the maximum amplitude will double the maximum velocity

(iii) Doubling the maximum amplitude will double the maximum acceleration: m×a = -k(2A)
(iv) Doubling the maximum amplitude leaves the period unchanged:
(neither m nor k has changed).