The mass of cesium left afer 120 years if the original mass of cesium is 8640 with an half-life of 30 years, is 540 grams.
<h3>What is half-life?</h3>
This can be defined as the time taken for half the amount of a radioactive substance to decay.
To calculate the amount of cesium left after 120 years, we use the formua below.
Formula:
- R' = R/(
)............. Equation 1
Where:
- R = Original amount of Cesium
- R' = New amount of cesium
- T = Total time
- t = Half-life
From the question,
Given:
- R = 8640
- T = 120 years
- t = 30 years
Substitute these values into equation 1
- R' = 8640/(
) - R' = 8640/

- R' = 8640/16
- R' = 540 grams.
Hence, The mass of cesium left afer 120 years is 540 grams.
Learn more about half-life here: brainly.com/question/25750315
Answer:
27
Step-by-step explanation:
4 times 4 is 16
2 boxes in the middle
4 tiny boxes in each one in the middle
1 entire one on the outside
1+4+4+2+16= 27
First subtract the two numbers:
8 - 5 = 3
Now divide this to the original:
3 / 5 = 0.6
Multiply by 100:
0.6 * 100 = 60%
Parameterize the lateral face

of the cylinder by

where

and

, and parameterize the disks

as


where

and

.
The integral along the surface of the cylinder (with outward/positive orientation) is then




Complete question:
A circle with radius 3 has a sector with a central angle of 1/9 pi radians
what is the area of the sector?
Answer:
The area of the sector =
square units
Step-by-step explanation:
To find the area of the sector of a circle, let's use the formula:

Where, A = area
r = radius = 3
Substituting values in the formula, we have:

The area of the sector =
square units