How do you find instantaneous speed?

[navneet]

how can I find the instantaneous speed when t=6 seconds for the following, and would it be any differnt if i draw a graph and find it using with the line of best fit.

d (m) l t (s)
---------------------------
0 l 0
2 l 1.59
4 l 2.37
6 l 3.87
8 l 3.98
10 l 6.09
12 l 8.90
14 l 8.66
16 l 9.23
18 l 10.18

 

[mathman]

Your approach is probably the most reasonable. There are formulas one could use, but they would effectively get the same result as you could by a good curve fit. The formulas are curve fitting themselves.