I drew a circle using the elliptical tool. Then I used the Stroke tool to increase the weight of the line of the circle and then used it to add a dashed line, so the circle looked like a dial. I used the gradient tool to add a gradient affect to further show that acceleration is taking place. I did this same technique again but I deleted half of the dashes so the dial is a semi circle.
I used the polar grid tool, using the same technique of the circle.
For the triangle I made some lines and then used the pathfinder tool to divide up the triangle.This symbol shows acceleration using the gradient of color to show the increase and decrease in speed. I grouped them together.
pathfinder, grouping and ungrouping