1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Mice21 [21]
3 years ago
12

A sample of 400 grams of radioactive substance decays according to the function A(t) = 400e^-.046t, where t is the time in years

. How much of the substance will be left in the sample after 20 years? Round your answer to the nearest whole gram.
Mathematics
1 answer:
algol133 years ago
6 0

Answer: There will be 0.04 grams will be left in the sample after 20 years.

Step-by-step explanation:

Since we have given that

A(t)=400e^{-0.46t}

Here, Initial amount of radioactive substance = 400 grams

We need to find the amount of substance that will be left in the sample after 20 years.

So, t = 20 years

So, it becomes,

A(t)=400e^{-0.46\times 20}\\\\A(t)=400e^{-9.2}\\\\A(t)=0.04\ grams

Hence, there will be 0.04 grams will be left in the sample after 20 years.

You might be interested in
A metalworker has a metal alloy that is 15​% copper and another alloy that is 60​% copper. How many kilograms of each alloy shou
coldgirl [10]

18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.

<u>Step-by-step explanation:</u>

Let x = kg of 15% copper alloy

Let y = kg of 60% copper alloy

Since we need to create 90 kg of alloy we know:

x + y = 90

51% of 90 kg = 45.9 kg of copper

So we're interested in creating 45.9 kg of copper

We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:

0.15x + 0.60y = 45.9

but

x + y = 90

x= 90 - y

substituting that value in for x

0.15(90 - y) + 0.60y = 45.9

13.5 - 0.15y + 0.60y = 45.9

0.45y = 32.4

y = 72

Substituting this y value to solve for x gives:

x + y = 90

x= 90-72

x=18

Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.

6 0
3 years ago
*ANSWER PLS TYY* Which of the following statements is TRUE about finding the area of a polygon? a.) You can use a coordinate pla
ruslelena [56]

Answer:

The answer to this question is b)

3 0
3 years ago
Read 2 more answers
Estimate the quotient<br><br><br>31.8 ÷ 16.2<br><br>show your work
11Alexandr11 [23.1K]
Round the problem

32/16 = 2


7 0
3 years ago
Read 2 more answers
Find (2x+4) (x-4) using the table of products. write your answer in standard form.​
ValentinkaMS [17]

Answer:

2x^2-4x-16

Step-by-step explanation:

6 0
2 years ago
What is the slope of the line shown?
Alina [70]

Answer:1/2 slope

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
Other questions:
  • Was i right on the first 2? Please correct them if i'm wrong
    8·1 answer
  • What is the answer for this problem?
    12·1 answer
  • 79. Revenue. The revenue (in dollars) from the sale of x infant car seats is given by R1x2 = 60x - 0.025x2 0 ... X ... 2,400 (A)
    7·1 answer
  • 739 is closer to ___ than it is to _____&lt;br /&gt;&lt;br /&gt;
    6·1 answer
  • The area of a playground is 266 yd. The width of the playground is 5 yd longer than its length. Find th
    9·1 answer
  • Can somebody solve this for me please?
    7·1 answer
  • GODD SOMEONE HELP ME RIGHT NOW PLEASE THIS IS DUE TODAY AND I AM DUM I GIVE POINTS AND BRAINLIEST JUST HELP MEEE
    10·1 answer
  • GIVING BRAINLIEST!
    14·1 answer
  • The points (3,5) and (21,35) form a proportional relationship. Find the slope of the line through thepoints. Then use the slope
    6·1 answer
  • Which function has a constant additive rate of change of 14
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!