Your engineering firm has been asked to determine the deceleration of a car during hard braking. To do so, you decide to measure the lengths of the skid marks when stopping from various initial speeds. Your data are as follows:

Speed (m/s)                           Skid length(m)

10 ................................................     7

15 ................................................    14

20 ................................................    27

25 ................................................    37

30 ................................................    58

a. Do the data support an assertion that the deceleration is constant, independent of speed? Explain.

b. Determine an experimental value for the car’s deceleration—that is, the absolute value of the acceleration. Your analysis method should involve fitting a straight line to an appropriate graph, similar to the analysis in Example 2.15.