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2 years ago

Help!! For first and second please

Mathematics

1 answer:

jenyasd209 [6]2 years ago

5 0

Answer:

it goes al the way up to 15 and it stops at 5 and the 8 makes the green house

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The polygons in each pair are similar find the scale factor smaller figure to the larger

GrogVix [38]

Answer:

Smaller Figure 3

Larger Figure 5

Scale factor = 15/25 = 3/5

3 0

2 years ago

Crystal is spinning the spinner at right and claims she has a good chance of having the spinner land on red at least once in thr

-BARSIC- [3]

Wouldn’t the answer be 1/3?

6 0

3 years ago

What is the answer to this inequality?<br> (x+7)>80

Crank

Answer:

x > 73

Step-by-step explanation:

x+7 > 80

subtract 7 from both sides

x + 7 - 7 > 80 - 7

x > 73

-Chetan K

5 0

2 years ago

Two different radioactive isotopes decay to 10% of their respective original amounts. Isotope A does this in 33 days, while isot

Andrews [41]

Answer:

The approximate difference in the half-lives of the isotopes is 66 days.

Step-by-step explanation:

The decay of an isotope is represented by the following differential equation:

$\frac{dm}{dt} = -\frac{t}{\tau}$

Where:

$m$ - Current mass of the isotope, measured in kilograms.

$t$ - Time, measured in days.

$\tau$ - Time constant, measured in days.

The solution of the differential equation is:

$m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }$

Where $m_{o}$ is the initial mass of the isotope, measure in kilograms.

Now, the time constant is cleared:

$\ln \frac{m(t)}{m_{o}} = -\frac{t}{\tau}$

$\tau = -\frac{t}{\ln \frac{m(t)}{m_{o}} }$

The half-life of a isotope ( $t_{1/2}$ ) as a function of time constant is:

$t_{1/2} = \tau \cdot \ln2$

$t_{1/2} = -\left(\frac{t}{\ln\frac{m(t)}{m_{o}} }\right) \cdot \ln 2$

The half-life difference between isotope B and isotope A is:

$\Delta t_{1/2} = \left| -\left(\frac{t_{A}}{\ln \frac{m_{A}(t)}{m_{o,A}} } \right)\cdot \ln 2+\left(\frac{t_{B}}{\ln \frac{m_{B}(t)}{m_{o,B}} } \right)\cdot \ln 2\right|$

If $\frac{m_{A}(t)}{m_{o,A}} = \frac{m_{B}(t)}{m_{o,B}} = 0.9$ , $t_{A} = 33\,days$ and $t_{B} = 43\,days$ , the difference in the half-lives of the isotopes is: