02 Kinematics

Notes

The following topics are covered in this chapter.

Define position relative to a reference point and understand that position can be positive or negative
Know that position is a vector quantity that points from the reference point as the origin
Define distance as the length of path travelled and know that distance is a scalar quantity
Define displacement as a change in position
Know that displacement is a vector quantity that points from the initial to the final position
Define speed as the rate of change of distance and know that speed is a scalar quantity
Define velocity as the rate of change of position (or displacement) and know that velocity is a vector quantity
Distinguish between average velocity and instantaneous velocity
Define acceleration as the rate of change of velocity

Notes

The following topics are covered in this chapter.

Explain that projectiles fall freely with gravitational acceleration 'g'. Where g = 9,8 m.s-2 near the surface of the Earth
Know that projectiles take the same time to reach their greatest height from the point of upward launch as the time they take to fall back to the point of launch

Notes

The following topics are covered in this chapter.

For either horizontal motion or vertical motion with constant acceleration:
Draw position vs time, velocity vs time and acceleration vs time graphs for one dimensional motion
Interpret graphs of motion:
- - Determine the velocity of an object from the gradient of a position (or displacement) vs time graph
- - Determine the acceleration of an object from the gradient of a velocity vs time graph
- - Determine the displacement of an object by finding the area under a velocity vs time graph

Notes

The following topics are covered in this chapter.

Use equations of motion to solve problems involving either horizontal motion or vertical motion with constant acceleration: $\begin{align*} \vec{v}_{f}& = \vec{v}_{i}+\vec{a}t \\ \Delta \vec{x}& = \frac{\left(\vec{v}_{i}+\vec{v}_{f}\right)}{2}t \\ \Delta \vec{x}& = \vec{v}_{i}t+\frac{1}{2}\vec{a}{t}^{2} \\ \vec{v}_{f}^{2}& = \vec{v}_{i}^{2}+2\vec{a}\Delta\vec{ x } \end{align*}$ $\begin{array}{ccc}\hfill \stackrel{\to }{u}& =& \text{initial}\phantom{\rule{4.pt}{0ex}}\text{velocity}\phantom{\rule{4.pt}{0ex}}\text{(}\phantom{\rule{0.166667em}{0ex}}\text{m}·{\text{s}}^{-1}\text{)}\phantom{\rule{4.pt}{0ex}}\text{at}\phantom{\rule{4.pt}{0ex}}t\phantom{\rule{4.pt}{0ex}}\text{=}\phantom{\rule{4.pt}{0ex}}\text{0}\phantom{\rule{4.pt}{0ex}}\text{s}\hfill \\ \hfill \stackrel{\to }{v}& =& \text{final}\phantom{\rule{4.pt}{0ex}}\text{velocity}\phantom{\rule{4.pt}{0ex}}\text{(}\text{m}·{\text{s}}^{-1}\text{)}\phantom{\rule{4.pt}{0ex}}\text{at}\phantom{\rule{4.pt}{0ex}}\text{time}\phantom{\rule{4.pt}{0ex}}t\hfill \\ \hfill \stackrel{\to }{s}& =& \text{displacement}\phantom{\rule{4.pt}{0ex}}\text{(m)}\hfill \end{array}$ Note: Both versions of the equations will be accepted. For the purpose of this document, u, v, a, t and s will be used

Displacement, Velocity and Acceleration