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
Tju [1.3M]
3 years ago
5

Situation:

Mathematics
1 answer:
Rzqust [24]3 years ago
8 0
N=NOe^-kt
N=mass at time t
NO = initial mass
k= 0.1476
t= time, in days

We are asked to find the half-life, which means you want to find how long it will take for half of the substance to decay/disappear (depending on situation). 

If we are looking for half-life, we can simply set N to half of NO (which we are given a value of 40grams for)
Therefore:
N = 20
NO = 40
plugging these values and the value given for k back into the equation you get:

20 = 40e^-0.1476(t)
We are looking for t, so we have to manipulate the formula to get t by itself on one side of the equation.
We can start by dividing 40 from both sides, and you get:
0.5 = e^-0.1476(t)

We have the exponential function "e".
To get rid of e, we can use natural log (ln)
if e^y=x then ln (x) = y
look back at our equation we can set
0.5 = x
-0.1476(t) = y

Rewriting it in natural log form:
ln (0.5) = -0.1476(t)
Plug in ln (0.5) on a calculator to find its value and we get:
-0.693147 = -0.1476(t)
*Note: normally, getting a negative value would suggest that we did something wrong, because you cannot have a negative value as your t (you cannot have negative days), but because there is a negative on both sides of the equation, they will cancel out in this case. 

The last step is to simply divide both sides by -0.1476
therefore:
T = 4.696119
But it asks you for the answer to the nearest tenth (one place after decimal pt) so 
T (half life) = 4.7 days

Hope that helps :)
You might be interested in
38.96 to the nearest tenth
RUDIKE [14]
39 , is your answer.
6 0
3 years ago
Last digit (unit digit) of 2^2014
Drupady [299]

Answer:

4

Step-by-step explanation:

Let's find a pattern.

2^0=1

2^1=2

2^2=4

2^3=8

2^4=16

2^5=32

2^6=64

2^7=128

2^8=256

So starting after power of 0, the pattern begins at power=1. The pattern is 2,4,8,6 for the units digit. Since the pattern repeats in 4, then we shall divide the power in question by 4 seeking it's remainder.

Remainder=1 implies unit digit is 2 (see 2^1=2)

Remainder=2 implies unit digit is 4 (see 2^2=4)

Remainder=3 implies unit digit is 8 (see 2^3=8)

Remainder=0 implies unit digit is 6 (see 2^4=16)

2014/4 = 503 + 2/4

So remainder=2 implies unit digit is 4.

7 0
3 years ago
I need help i only have 5 min left
kirza4 [7]

Answer:

find the slope then use this y-y1=m(x-x1)

Step-by-step explanation:

6 0
3 years ago
The perimeter of the scalene triangle is 54.6cm, which equation can be usted to find the value of b if side a measures 8.7 cm?
Delicious77 [7]

Answer:

b= 45.9 cm

Step-by-step explanation:

5 0
3 years ago
Find the area of the shaded region please.
Ira Lisetskai [31]
The first shaded triangle is 144 cm. 
7 0
3 years ago
Other questions:
  • M< AOB + m < 96= m <139
    13·1 answer
  • Help and explain plzzzzzz
    7·2 answers
  • Two children share 2 ½ chocolate bars with each child getting the same amount. how much does each child get?
    13·1 answer
  • What is the cube root of ______?
    6·1 answer
  • I need to know who is right
    13·1 answer
  • A bicycle wheel has a diameter of 24inches. <br> what is the area of the wheel?
    14·1 answer
  • You put 40% of your paycheck into your savings account. If you earned $180 on your paycheck, then how much money did you put int
    12·1 answer
  • Consider if each set of ordered pairs represents a function
    14·1 answer
  • Please help me to solve the 7th part !​
    5·1 answer
  • how can you fluently add, subtract, mulitply, and divide decimals? how can you multiply and divide fractions?​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!