The integral of acceleration is velocity. The area under the curve is an integral. You can see the relation here. So just take the area under those time intervals. I’m assuming 1.7 is where it crosses the x-axis
For the first interval: Base = 1.7 Height = -2 [1.7*(-2)]/2 = -1.7 cm/s
For the second interval: There are two triangles and a rectangle here. Base #1 = 0.3 Height #1 = 1
Base #2 = 1 Height #2 = 1
Length = 3 Width = 1
Apply the area formulas to get an answer of 3.65 cm/s
