Acceleration & the Motion of Cars- 09/23/11

Today's class began with a weekly quiz, which focused on determining velocity and various forms of acceleration through the use of a Velocity-Time graph. From the graph we were asked to find instantaneous acceleration (acceleration of an object at a specific time), average acceleration (the rate of change of an object's velocity per unit of time), instantaneous velocity (velocity of an object at a specific time), and displacement (the change in position of an object) by finding the area of the desired time period. The formulas for the aforementioned vector quantities are as follows:

Instantaneous Acceleration/Average Acceleration- Δv/Δt

Displacement (from a Velocity-Time Graph)- if the area is a triangle: (1/2)bh, if the area is a rectangle: lw

We also had to recognize negative acceleration (which occurred above the x axis and was therefore still a continuation in direction, as compared to negative acceleration which crosses the x axis and would represent a change in the direction).

For the remainder of the class, we continued to work on the Motion of Cars Investigation. With the data collected, we were able to draw graphs and address the accompanying questions; knowledge on the different types of acceleration, velocity, and how to determine displacement were key. We were required to draw Position-Time graphs, which we could create simply by looking at the data collected, as well as a Velocity-Time graph. To create the latter graph, we determine the instantaneous velocity for each point in time using the formula v= Δd/Δt. An example of a Velocity-Time graph can be seen below:

Amanda is next.