Question

MAJORRRR HElppp

Answer 1

Answer:

Step 1: Finding r using the formula ln 2/h

$1.\ r=\frac{ln\ 2}{h}\\ r=\frac{ln\ 2}{140}\\r=0.00495$

Step 2: Substitute the values in given formula

$2.\ m_t=m_0e^{-rt}\\200=300e^{-0.00495t}$

Step 3: Divide both sides by 300

$\frac{2}{3} =e^{-0.00495t}$

Step 4:  Take the natural logarithm on both sides

$ln\ \frac{2}{3} =ln\ e^{0.00495t}$

Step 5: Simplify

$-0.405 = -0.00495t$

Step 6: Divide both sides by 0.00495

$\frac{-0.405}{-0.00495} =t$

Step 7: Simplify

$t=81.8\ days$