v(t) of an object of mais M in freefall satisfies a differential equation \[\\frac{d e}{d t}=\frac{-k} {M}\left(v+\frac{M \cdot g}{k} ight). \] Where 9 = 9.8- m m is the constant acceleration due to gravity and k is the air tesistance constant. tecminal velocity mph Note: Answer should be negative for downward velocity