Study of forces.
| variable | meaning | unit |
|---|---|---|
| F | force | N = \frac{kg \cdot m}{s^2} |
| p | momentum | \frac{kg \cdot m}{s} |
| p | friction | 1 |
F = ma
p = mv
static friction:
for a given U(x, y) potential: F_x = - \frac{\delta Y}{\delta x}, F_y = - \frac{\delta Y}{\delta y}
dU = - F_xdx - F_ydy = - \vec{F} \cdot d\vec{r}
Elastic: Two objects colliding (prime indicates the velocity after the collision): m_1v_1 + m_2v_2 = m_1v_1' + m_2v_2'
Inelastic: Two objects colliding and sticking together (prime indicates the velocity after the collision): m_1v_1 + m_2v_2 = v'(m_1 + m_2)