Related Rates: rate of change of the speed of sound with respect to temperature.

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The speed of sound, v, in air is a function of the temperature, T, of the air:

$v = 331.4 + 0.6(T − 273)$

with v in meters per second and T in kelvins

Suppose the rate of change of air temperature is $-0.11 \frac{K}{min}$.

  1. Find the rate of change of the speed of sound with respect to time.

  2. Find the rate of change of the speed of sound with respect to temperature.


I found the answer to part one by taking the derivative of the original function:

  • $ v'= 0.6(T')$

  • $v'=0.6(-0.11)$

  • $v'= -0.066 \frac{m/s}{min}$

What I know about part two:

  • Units are in $\frac{m/K}{min}$

  • $0.6$ is in units of $\frac{m/s}{K}$

What I have tried:

  • Since I know the units are in $\frac{m/K}{min}$ , I hypothesized changing the units of $-0.11 \frac{K}{min}$ into $\frac{K}{s}$ in order to cancel out the unit of $s$ to arrive at units in $\frac{m/K}{min}$

  • $v'=0.6 \frac{m/s}{K}\cdot-0.0011 \frac{K}{s}$

  • $v' = -0.00066$

This is not the correct answer. Can someone put me on the right track to arrive at $\frac{m/K}{min}$? Is my hypothesis wrong?