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azamat
2 years ago
6

The half-life of a radioactive element is five years. A scientist has 18 grams of the element. The equation

Mathematics
1 answer:
lianna [129]2 years ago
7 0

Answer:

The equation that describes the amount of mass left after a time t of a radioactive isotope is the following:

where

is the mass of the sample at t = 0

is the half-life of the sample

For the element X in this problem,

We want to find the time t at which

So we need to re-arrange the equation making t the subject:

Step-by-step explanation:

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PLEASE HELP quickly ​
sergejj [24]

Answer:

C. Radius or diameter must be known.

Step-by-step explanation:

The radius or diameter must be known so you can use the formula.

Hope this helps!

4 0
2 years ago
When multiplying and dividing two numbers in scientific notation, why do u sometimes have to rewrite one factor ?
zalisa [80]

You sometimes need to rewrite a factor because the lead number is not between 1 and 10 as it needs to be in scientific notation. For instance, if we had lead numbers of 2 and 5, as we do in the following problem.

2x10^3 * 5x10^9

Then we get the answer of 10x10^12. We need to adjust this by moving the decimal place and increasing the exponent by 1. The correct answer would be 1x10^13 instead.

5 0
3 years ago
Read 2 more answers
Y raise to power 1/2 =3​
marta [7]

Answer:

y = root 9

Step-by-step explanation:

1/2 is equivalent to the root of something.

The root of y equals 3.

Therefore, y would be equal to root 9, as root 9 is equivalent to 3.

Hope this helps :)

6 0
2 years ago
Read 2 more answers
Exhibit B: A restaurant has tracked the number of meals served at lunch over the last four weeks. The data shows little in terms
Mekhanik [1.2K]

Answer:

Option E is correct.

The expected number of meals expected to be served on Wednesday in week 5 = 74.2

Step-by-step Explanation:

We will use the data from the four weeks to obtain the fraction of total days that number of meals served at lunch on a Wednesday take and then subsequently check the expected number of meals served at lunch the next Wednesday.

Week

Day 1 2 3 4 | Total

Sunday 40 35 39 43 | 157

Monday 54 55 51 59 | 219

Tuesday 61 60 65 64 | 250

Wednesday 72 77 78 69 | 296

Thursday 89 80 81 79 | 329

Friday 91 90 99 95 | 375

Saturday 80 82 81 83 | 326

Total number of meals served at lunch over the 4 weeks = (157+219+250+296+329+375+326) = 1952

Total number of meals served at lunch on Wednesdays over the 4 weeks = 296

Fraction of total number of meals served at lunch over four weeks that were served on Wednesdays = (296/1952) = 0.1516393443

Total number of meals expected to be served in week 5 = 490

Number of meals expected to be served on Wednesday in week 5 = 0.1516393443 × 490 = 74.3

Checking the options,

74.3 ≈ 74.2

Hence, the expected number of meals expected to be served on Wednesday in week 5 = 74.2

Hope this Helps!!!

8 0
3 years ago
Please help ASAP!!!!!!
stealth61 [152]

Answer:

heart no, square yes, circle yes, triangle no, hexagon no

Step-by-step explanation:

5 0
3 years ago
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