What is the product.... <br><br> (1.017)•(0.072)=

A 41 gram sample of a substance that's used to detect explosives has a k-value of 0.1392. Find the substance's half life, in day

-BARSIC- [3]

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:

$A(t) = A(0)e^{-kt}$

In which k is the decay rate, as a decimal.

k-value of 0.1392.

This means that:

$A(t) = A(0)e^{-0.1392t}$

Find the substance's half life, in days.

This is t for which $A(t) = 0.5A(0)$ . So

$A(t) = A(0)e^{-0.1392t}$

$0.5A(0) = A(0)e^{-0.1392t}$

$e^{-0.1392t} = 0.5$

$\ln{e^{-0.1392t}} = \ln{0.5}$

$-0.1392t = \ln{0.5}$

$t = -\frac{\ln{0.5}}{0.1392}$

$t = 4.98$

The substance half-life is of 4.98 days.

5 0

3 years ago

6. A sporting goods store receives an order of 100 baseball caps, of which 22 are green. If 1 of

Taya2010 [7]

Answer:

$\text{A. }39/50$

Step-by-step explanation:

The probability that a randomly selected cap will not be green is equal to the number of non-green caps divided by the total number of caps.

Since there are 100 caps total and 22 are green, there must be $100-22=78$ non-green caps.

Divide this by the total number of caps (100) to get the probability that a randomly selected cap will not be green:

$\frac{78}{100}$

Simplify by dividing both the numerator and denominator by 2:

$\frac{78}{100}=\boxed{39/50}$

6 0

3 years ago

100 POINTS!!! Orthographic projection and isometric projection are two ways to show three-dimensional objects in a two-dimension

shutvik [7]

Example 1:

The pros of Orthographic is that they can show hidden details and all of the connecting parts, they can be annotated to display material and finishes. The pros of Isometric projection is that they dont need many views and it gives accuracy, cons are is created a unorginized apperance by the lack of foreshortening, I would choose Isometric projection because it shows the size of the figure.

Example 2:

Orthographic projection is a good option for showing lots of detail and small things. The limitation is that with all of that detail, they can become quite messy and hard to understand to someone new to them. However, that is one of the pros of Isometric projection. It gives easy detail and is just as good as an Orthographic. Personally, I find Isometric projections easier to interpret.

4 0

3 years ago

Read 2 more answers

a total of $9500 is invested, part at 10% simple interest and part at 9%. if the total annual return from the two investments is

Nutka1998 [239]

a total of $9500 is invested, part at 10% simple interest and part at 9%

if the total annual return from the two investments is $914.00

Amount invested = 9500

Total amount return means total yield = $914

Let x amount is invested at 10% simple interest

Interest for first part = 10 % times x = 0.10x

Remaining part invested is 9500 -x

Interest for remaining amount = 9% (9500 -x) = 0.09(9500-x)

Total interest yield is 914. Now we frame an equation

0.10x + 0.09(9500-x) = 914

0.10x +855 - 0.09x = 914 (combine like terms)

0.01 x + 855 = 914 (subtract 855)

0.01x = 59 ( divide both sides by 0.01)

So x = 5900

$5900 is invested in 10% simple interest

9500 - 5900 = $3600 is invested in 9% simple interest

3 0

3 years ago

What is the perimeter of a quadrilateral with vertices at (3,-6),(8,-6),(3,-4), and (8,-4)

Eduardwww [97]

Answer:

im sorry i dont know but this is for a challenge

Step-by-step explanation:

3 0

2 years ago

What is the product.... (1.017)•(0.072)=