mechanics
Impulse-Momentum Theorem
$$J = \Delta p = F \Delta t$$
Pendulum Period/Frequency
$$T_p = 2 \pi \sqrt{\frac{\ell}{g}}$$
Spring Period/Frequency
$$T_s = 2 \pi \sqrt{\frac{m}{k}}$$
Hooke's Law (Spring Constant)
$$F = -kx$$
Newton's 2nd Law
$$F = ma$$