Constant Acceleration Problems

• We started off the class by reviewing how to change a velocity-time graph into a distance-time graph or an acceleration-time graph. The steps are as follows:
  

Distance-Time Graph

1) Find the displacement (area) of different time intervals on the velocity-time graph.

2) Plot several points based on the displacement found in part one.

3) Use your knowledge about velocity to connect the points. Ex: You have two points, one at 2.0s and the other at 5.0s. Look at the velocity-time graph to see if the velocity was constant or changing between 2.0-5.0s. If it was constant, connect the points with a straight line. If the velocity was increasing, connect the points with a positively curved line, etc.

Acceleration-Time Graph

1) Find the slope of several different time intervals on the velocity-time graph. The slope indicates the acceleration of the object.

2)Use the calculated slope to draw your graph. Ex: If you find the slope to be 7.5cm/s from 2.0-5.0s, draw a straight line on the acceleration-time graph at 7.5 on the y-axis from 2.0-5.0 on the x-axis.

3) Whenever there is a straight horizontal line on the velocity-time graph, there is no acceleration.

4) Keep in mind that the acceleration-time graphs drawn at a Physics 30 level don't wouldn't usually make sense in a real life situation.

• Next we moved on to some constant acceleration problems.
  


• Some important points to remember when solving acceleration problems are:
  i) We cannot calculate the answer properly unless the question states that the acceleration is uniform.
  ii) An object that starts from rest has a $V1$ of 0.
  iii) Whenever gravity is acting on the object in question, the object has an acceleration due to gravity of $a=9.8m/s^2$
  iv) When selecting the formula to solve the problem, you should list all of the known variables and the variable that you are trying to solve for. You should be able to select the proper formula simply by looking at which variables are present.
  v) Formulae can be manipulated
  


• We finished off the class by starting a work booklet. The booklet is composed of questions that analyze all of the graphs we have learned about thus far.

Landon is next.