the weight of the substance after 28 years is 8 grams.
<h3>How to determine the amount</h3>
We have that the half life of a substance is defined as the time required for the substance to decrease by half
The formula for calculating the half - life of a material is given as;
Where
- N(t) is final amount
- No is the initial amount = 128 grams
- t1/2 is the half life = 7 years
- t is the time elapsed = 28 years
Substitute into the formula
N(t) = 128 × (0. 5) ^28/ 7
N (t) = 128 × ( 0. 5) ^ 4
N(t) = 128 × 0. 0625
N(t) = 8 grams
Thus, the weight of the substance after 28 years is 8 grams.
Learn more about half life here:
brainly.com/question/26148784
#SPJ1
Answer:
m∠1 = 63°
m∠2 = 49°
m∠3 = 87°
m∠4 = 44°
Step-by-step explanation:
From the given figure
∵ ∠2 and 49° are vertically opposite angles
∵ The vertical opposite angles are equal in measures
∴ m∠2 = 49°
∵ The sum of the interior angles of a Δ is 180°
∵ m∠1, m∠2, and 68° are interior angles of a Δ
∴ m∠1 + m∠2 + 68° = 180°
∵ m∠2 = 49°
∴ m∠1 + 49° + 68° = 180°
→ Add the like terms in the left side
∴ m∠1 + 117 = 180
→ Subtract 180 from both sides
∴ m∠1 = 63°
∵ ∠3 and 93° formed a pair of linear angles
∵ The sum of the measures of the linear angles is 180°
∴ m∠3 + 93° = 180°
→ Subtract 93 from both sides
∴ m∠3 = 87°
∵ 93° is an exterior angle of the triangle
∵ The measure of the exterior angle of a Δ at one vertex equals the sum
of the measures of the opposite interior angles to this vertex
∵ ∠4 and 49° are the opposite interior angles to 93°
∴ 49° + m∠4 = 93°
→ Subtract 49 from both sides
∴ m∠4 = 44°
Hello!
The cylinder shown has a lateral surface area of about 80 square inches. Which answer is closest to the height of the cylinder? Use 3.14 to approximate pi.
We have the following data:
Al (lateral surface area) = 80 in²
R (ratio) = 4 in
h (height) = ? (in inches)
Adopt : π ≈ 3.14
We apply the data to the formula, we have:
Answer:
≈ 3.2 inches
________________________
<em>Answer: 52</em>
<em />
<em>Step-by-step explanation:</em>
<em>8x6+(12-4)÷2</em>
<em>Parenthesis' first</em>
<em>8x6+8÷2</em>
<em>multiplication next</em>
<em>48+8÷2</em>
<em>Division next</em>
<em>48+4</em>
<em>52</em>
Give me a question i can answer. i might could help.
