Table of Contents
Kinematic Equations
- $V = \frac{\Delta \text{position}}{\Delta \text{time}}$1)
- $V_f = V_i + at$
- $V_f^2 = V_i^2+2aD$
- $D = V_it + \frac{1}{2}at^2$
- $D = V_ft - \frac{1}{2}at^2$
- $D = \frac{1}{2}(V_f + V_i)t$
Take note of the missing variable for each equation, these don't have to be memorized since they are clearly derived from one root function.
Definitions
Vector
A vector quantity includes direction within its value. Acceleration and Velocity are vector quantities.
Scalar
Scalar quantities don't, speed is the obvious one.
Free Fall
When an object is in free fall, gravity is the only force affecting the object. Useful for narrowing forces for calculation.
Example
A car starts at rest and accelerates at 3 m/s^2 for 8 seconds. How far did it go?
Variables
- $V_i = 0$ m/s
- $a = 3$ m/s^2
- $t = 8$ seconds
Equation(s)
- $D = V_it + \frac{1}{2}at^2$
- $D = 0(8) + \frac{1}{2}3(8^2)$
- $D = 0 + 96$
- $\boxed{D = 96 m}$
- $V_f = V_i + at$
- $V_f = 0 + 3(8)$
- $\boxed{V_f = 24 m/s}$
1)
displacement is the change in position, and velocity is that over time