Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:
In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:
Find the substance's half life, in days.
This is t for which 
. So
The substance half-life is of 4.98 days.
You need to multiply the base by the height.
Answer:
12
Step-by-step explanation:
We are given a concave spherical mirror with the following dimensions:
Radius = 60 cm; D o = 30 cm
Height = 6 cm; h o = 6 cm
First, we need to know the focal length, f, of the object (this should be given). Then we can use the following formulas for calculation:
Assume f = 10 cm
1/ f = 1 /d o + 1 / d i
1 / 10 = 1 / 30 + 1 / d i
d i = 15 cm
Then, calculate for h i:
h i / h o = - d i / d o
h i / 6 = - 15 / 30
h i = - 3 cm
Therefore, the distance of the object from the mirror is 3 centimeters. The negative sign means it is "inverted".
A = D/BC. In order to isolate A, all you do is divide by BC
