1: Mass (m), 2: Spring (k), 3: Equilibrium position.

1: Length (L), 2: Mass (m), 3: Angle of displacement ($\theta$).

Increasing the mass increases the period (T).

Increasing the spring constant decreases the period (T).

Increasing the length increases the period (T).

Increasing gravitational acceleration decreases the period (T).

The velocity is at its maximum value.

The acceleration is at its maximum value and directed towards the equilibrium position.

Take the first derivative of the position function with respect to time: $v(t) = \frac{dx(t)}{dt} = -A\omega \sin(\omega t + \phi)$.

Take the first derivative of the velocity function with respect to time: $a(t) = \frac{dv(t)}{dt} = -A\omega^2 \cos(\omega t + \phi)$.

Use the formula: $T = 2\pi \sqrt{\frac{m}{k}}$, where m is the mass and k is the spring constant.

Use the formula: $T = 2\pi \sqrt{\frac{L}{g}}$, where L is the length of the pendulum and g is the acceleration due to gravity.

Sum the kinetic and potential energies: $ME = K + U$, where $K = \frac{1}{2}mv^2$ and $U = \frac{1}{2}kx^2$ (for a spring) or $U = mgh$ (for gravity).