Question $10$:A ball is attached to a string hanging from the ceiling, forming a pendulum. The mass of the string is negligible compared with the mass of the ball. At time $,$ the pendulum is shifted from the vertical by an angle and then let go$,$ starting from rest. The angle is quite small, so that the approximation is excellent. Which of the statements below is most correct?$1.$The period of oscillation is proportional to $,$ so that if this angle is doubled, the time it takes for the pendulum to complete an oscillation also doubles$\mathrm{.}2.$The period of oscillation is inversely proportional to the square root of the mass attached to the string$\mathrm{.}3.$The period of oscillation is proportional to the square root of the acceleration of gravity$\mathrm{.}4.$If the length of the string is quadrupled, the period of oscillation doubles$\mathrm{.}5.$The period of oscillation is proportional to the square root of the mass attached to the string.