Question

Water is poured into a container that has a small leak. The mass $m$ of the water is given as a function of time $t$ by $m=5.00t^{0.8}-3.00t+20.00$, with $t\ge 0,m$ in grams, and $t$ in seconds.
In kilograms per minute, what is the rate of mass change at $t=2.00s$

Answer 1

Mass is given in the function of time

$m=5.00t^{0.8}-3.00t+20.00$
The rate of mass charge at $t=2.00s$ is
$R=\frac{dm}{dt}{|}_{t=2.00s}=\left[4.00\right(2.00{)}^{-0.2}-3.00]g/s=0.48g/s=0.48\frac{g}{s}.\frac{1kg}{1000g}.\frac{60s}{1min}$

$R=2.89\times {10}^{-2}kg/min$.