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xxMikexx [17]
3 years ago
11

Element X is a radioactive isotope such that every 30 years, its mass decreases by half. Given that the initial mass of a sample

of Element X is 100 grams, how long would it be until the mass of the sample reached 64 grams, to the nearest tenth of a year?
Mathematics
1 answer:
Lena [83]3 years ago
8 0

Answer:

19.3 years

Step-by-step explanation:

Given that the initial mass of a sample of Element X is 100 grams,

The formula is given as:

N(t) = No × (1/2) ^t/t½

Element X is a radioactive isotope such that every 30 years, its mass decreases by half.

N(t) = Mass after time (t)

No = Initial mass = 100 grams

t½ = Half life = 30 grams

N(t) = 100 × (1/2) ^t/30

How long would it be until the mass of the sample reached 64 grams, to the nearest tenth of a year?

This means we are to find the time

N(t) = 100 × (1/2) ^t/30

N(t) = 64 grams

64 = 100(1/2)^t/30

Divide both sides by 100

64/100 = 100(1/2)^t/30/100

0.64 = (1/2)^t/30

Take the Log of both sides

log 0.64 = log (1/2)^t/30

log 0.64 = t/30(1/2)

t = 19.315685693242 years

Approximately = 19.3 years

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agasfer [191]

Answer:

Width              Length

5                        8.7

7.9                    11.6

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13                      16.7

Step-by-step explanation:

If they gave you the width, you add 3.7 to get the length.

If they gave  you the length, you subtract 3.7 to get the width.

4 0
3 years ago
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Nataly_w [17]
19.00 3.50 11.00 4.47 makes it add up to hours so that will be answe C
3 0
3 years ago
Please help me. It’s geometry
Verizon [17]

Option 3:

m∠ABC = 66°

Solution:

Given \overline {F A D} \| \overline {E H C} and ABH is a transversal line.

m∠FAB = 48° and m∠ECB = 18°

m∠ECB = m∠HCB = 18°

<u>Property of parallel lines: </u>

<em>If two parallel lines cut by a transversal, then the alternate interior angles are equal.</em>

m∠FAB = m∠BHC

48° = m∠BHC

m∠BHC = 48°

<u>Exterior angle of a triangle theorem: </u>

<em>An exterior angle of a triangle is equal to the sum of the opposite interior angles.</em>

m∠ABC = m∠BHC + m∠HCB

m∠ABC = 48° + 18°

m∠ABC = 66°

Option 3 is the correct answer.

4 0
3 years ago
Find the area of the parallelogram with vertices:________.
marin [14]

Answer:

97.98

Step-by-step explanation:

The area of the parallelogram PQR is the magnitude of the cross product of any two adjacent sides. Using PQ and PS as the adjacent sides;

Area of the parallelogram = |PQ×PS|

PQ = Q-P and PS = S-P

Given P(0,0,0), Q(4,-5,3), R(4,-7,1), S(8,-12,4)

PQ = (4,-5,3) - (0,0,0)

PQ = (4,-5,3)

Also, PS = S-P

PS = (8,-12,4)-(0,0,0)

PS = (8,-12,4)

Taking the cross product of both vectors i.e PQ×PS

(4,5,-3)×(8,-12,4)

PQ×PS = (20-36)i - (16-(-24))j + (-48-40)k

PQ×PS = -16i - 40j -88k

|PQ×PS| = √(-16)²+(-40)²+(-88)²

|PQ×PS| = √256+1600+7744

|PQ×PS| = √9600

|PQ×PS| ≈ 97.98

Hence the area of the parallelogram is 97.98

3 0
3 years ago
8.4 + 0.18x = 0.32x
bogdanovich [222]

Answer:

  x = 60

Step-by-step explanation:

Perhaps you want the solution to this equation.

Subtract 0.18x from both sides:

  8.4 = 0.14x

Divide by the coefficient of x.

  8.4/0.14 = x = 60

3 0
4 years ago
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