All categories

2 years ago

You have 2,112 grams of a radioactive kind of mercury. How much will be left after 188 days if it's half-life is 47 days?

Mathematics

1 answer:

Anastasy [175]2 years ago

4 0

Answer:

132 g

Step-by-step explanation:

Initial amount = 2112 g
Time = 188 days
Half-life = 47 days

188 days / 47 days = 4 periods

<u>Mercury left after 188 days:</u>

2112 * (1/2)^4 =
2112* 1/16 =
2112/16 =
132 g

You might be interested in

Compound interest of $1000 is invested at 10% compounded continuously, the future value s at any time t in years is given by s=1

crimeas [40]

Answer: 6.93 years

Step-by-step explanation:

Given

Rate of interest is $r=10\%$

Future value is given by $s=1000e^{0.1t}$

For the investment to double itself, i.e. $s=2000$

$\Rightarrow 2000=1000e^{0.1t}\\\Rightarrow 2=e^{0.1t}\\\\\text{Taking log both sides}\\\\\Rightarrow \ln 2=0.1t\\\\\Rightarrow t=\dfrac{\ln 2}{0.1}\\\\\Rightarrow t=6.93\ \text{years}$

It takes around 6.93 years to double the investment.

8 0

2 years ago

Please help 5 questions I need help

creativ13 [48]

Answer:

1. <2, <7

2. 58

3. 78

4. a and b

h5. <2 and <7 ( i think this is the same question as the first one)

Step-by-step explanation:

2. 2x + 7 = 123 (you have to make them equal to each other because they are consecutive interior angles)

2x + 7 = 123, subtract 7

2x = 116, divide 2 for both sides to make x by itself

x = 58

3. 78 because of consecutive interior angles

4 0

2 years ago

What is the perimeter of RSTUV?

MrMuchimi

Answer:

this should be 132 units i hope this helps! :)

Step-by-step explanation:

so these figures are similar

we are given 3 side measurements on one, and 3 on the other

we know that side BA is 10 units, and that SR which is the same side, is 14 units

we can conclude that they added 4 units to this side

so with the other side lengths that we are given we can figure out what the length of the perimeter of RSTUV is

10 + 4 = 14

15 + 4 = 19

28 - 4 = 24

42 - 4 = 38

25 + 4 = 29

42 TU

28 UV

19 VR

14 SR

29 ST

add all the side together to get 132 units

3 0

3 years ago

What is the simplified form of 2/x^2-x - 1/x?

Pachacha [2.7K]

Answer: $\bold{(C)\ \dfrac{3 - x}{x(x-1)}}$

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

$\dfrac{2}{x^2-x}-\dfrac{1}{x}$

$=\dfrac{2}{x(x-1)}+\dfrac{-1}{x}$

$=\dfrac{2}{x(x-1)}+\dfrac{-1}{x}\bigg(\dfrac{x-1}{x-1}\bigg)$

$=\dfrac{2}{x(x-1)}+\dfrac{-x+1}{x(x-1)}$

$=\dfrac{2-x+1}{x(x-1)}$

$=\dfrac{3-x}{x(x-1)}$

8 0

3 years ago

An animal shelter estimates that it costs about $6 per day to care for each dog. If y represents the total cost of caring for a

TEA [102]

Answer:

A 2-column table with 3 rows. Column 1 is labeled x with entries 12, 15, 18. Column 2 is labeled y with entries 6, 9, 12.

Step-by-step explanation:

A 2-column table with 3 rows. Column 1 is labeled x with entries 12, 15, 18. Column 2 is labeled y with entries 6, 9, 12.

7 0

2 years ago