31

*August*[accordions `autoHeight='true'`

]

[accordion title=”1. Definitions”]

**Displacement**is the distance travelled along a specified direction.**Speed**is the rate of change of distance travelled.**Velocity**is the rate of change of displacement.**Acceleration**is the rate of change of velocity.

[/accordion]

[accordion title=”2. One-Dimensional Motion with Constant Acceleration”]

- $$v=u+at$$
- $$s=(\frac{u+v}{2})t$$
- $$s=ut+\frac{1}{2}at^2$$
- $$v^2=u^2+2as$$

*s*: displacement

*u*: initial velocity

*v*: final velocity

*a*: acceleration

*t*: time

[/accordion]

[accordion title=”3. Two-Dimensional Motion”]

- Tip: Sometimes, you will require two equations to solve a kinematics problem. For a parabolic path in a projectile motion without resistive forces, you can draw a table such as the one below and fill in the blank with the information given in the question.

- In the case where a projectile is launched at an angle $$\theta$$ to the horizontal and undergoes the acceleration of free fall, the various horizontal and vertical components of displacement, velocity and acceleration can be expressed in the following way:

Horizontal | Vertical | |

displacement, s | $$(u \cos \theta)t$$ | $$(u \sin \theta)t+\frac{1}{2}gt^2$$ |

initial velocity, u | $$u \cos \theta$$ | $$u \sin \theta$$ |

initial velocity, v | $$u \cos \theta$$ | $$u \sin \theta +gt$$ |

acceleration, a | 0 | $$g$$ |

time, t | same for | both dimensions |

[/accordion]

[/accordions]