Answer:
105 years
Step-by-step explanation:
Given the function :
Q(t) = 4e^(-0.00938t)
Q = Quantity in kilogram of an element in a storage unit after t years
how long will it be before the quantity is less than 1.5kg
Inputting Q = 1.5kg into the equation:
1.5 = 4e^(-0.00938t)
Divide both sides by 4
(1.5 / 4) = (4e^(-0.00938t) / 4)
0.375 = e^(-0.00938t)
Take the ln of both sides
In(0.375) = In(e^(-0.00938t))
−0.980829 = -0.00938t
Divide both sides by 0.00938
0.00938t / 0.00938 = 0.980829 /0.00938
t = 104.56599
When t = 104.56599 years , the quantity in kilogram of the element in storage will be exactly 1.5kg
Therefore, when t = 105 years, the quantity of element in storage will be less than 1.5kg
