Acceleration Unit 1: Motion

I CAN... Explain acceleration and use the acceleration formula to solve problems

Velocity, Speed, and Acceleration Acceleration is the rate of change of velocity Recall: velocity tells both the speed and direction of motion and a rate of change means the change over a time period

Speeding Up & Slowing Down We tend to think of accelerating as being synonymous with increasing speed. However, any change in speed (increasing or decreasing in nature) is a change in velocity and therefor acceleration.

When speed increases we refer to it as a positive acceleration When speed decreases we refer to it was a negative acceleration Both pulling out from and stopping at a stop sign are types of acceleration

Changing Direction Every time a moving object changes direction, it's velocity changes. If velocity changes, the object is accelerating. Think about driving around the block, or going cruising. With every turn you take, you are accelerating-- even if your speed never changes!

Calculating Acceleration Acceleration is the change in velocity over time. The change in velocity can be found by subtracting the initial velocity from the final velocity Change in velocity = Vf - Vi Acceleration = change in velocity Vf - Vi Time t

Check your units!!! Velocity is given in m/s and a direction Acceleration is velocity over time Acceleration should be given in meters per second squared!

Practice Problems See worksheet

Solving for position and velocity If acceleration is CONSTANT, the following equations can be used: v= vo +at x= xo + vot +(1/2)at2 v2= vo2 + 2a(x-xo)

Variables V= velocity X= position T= time A= acceleration A “o” indicates the beginning condition (ex vo means the velocity at the beginning of the problem)