a 33 gram sample of a substance that's used for drug research has a k-value of 0.1142. fine the substance's half-life, in days. round to the nearest tenth. n0=initial mass (at time t=0) n=mass at time t k=positive constant that depends on the substance itself and on the units used to measure time t=time, in days

The half life of the substance is 6.0 days.

Step-by-step explanation:

The initial equation for the initial mass and mass at time t is;

                                N =

Where N is the mass at time t, is the initial mass, k is the constant and t is the half life. After the half life i.e t,

So that at a given time t, = 33 grams and N = 16.5 grams

        ⇒       16.5 = 33

                  16.5 =

cross multiply, we have;

                =

                  = 2

Find the natural logarithm of both sides,

          ln  = ln2

          kt = ln2

 ⇒     t =

         t =

         t = 6.07

The half life of the substance is 6.0 days.

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong

10 down (bang1)

5 up

5down (2)

2.5 up

2.5 down (3)

1.25 up

1.25 down (4)

now add them up : )

hoped i lol