Step-by-step explanation:
half life time-50%-8.4hr
so for 10%- 8.4/5=1.68 hr
now for 70%
1.68 × 7 = 11.76 hrs
to one decimal place - 11.8hrs
11.8 hours ago, there were 70% more of the substance if an isotope of lead has a half-life of 8.4 hours.
What is half-life?Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.
Half-life period - 50% -8.4hours
so for 10%- 8.4/5 = 1.68 hour
now for 70%
1.68 × 7 = 11.76 hours
To one decimal place - 11.8hours
Hence, 11.8hours is the answer.
To learn more about half-life here
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Find the sine and cosine of each angle as a fraction and as a decimal. Round to the nearest hundredth.
Answer:
1st triangle:
sin(C): 0.64, [tex]\frac{16}{25}[/tex]
cos(C): 0.8, [tex]\frac{4}{5}[/tex]
Second triangle:
sin(C): 0.75, [tex]\frac{\sqrt{5} }{3}[/tex]
cos(C): 0.67, [tex]\frac{2}{3}[/tex]
Step-by-step explanation:
Using SOH CAH TOA, we know that to find the sin of an angle, it's Opposite/Hypotenuse.
To find the cos of an angle, it's adjacent/hypotenuse.
In the 1st triangle:
The adjacent to C is 16, the hypotenuse is 25.
[tex]\frac{16}{25} = 0.64[/tex] is the sin of C.
The adjacent to C is 20, and the hypotenuse is 25.
[tex]\frac{20}{25} = 0.8[/tex] is the cos of C.
In the second triangle:
The opposite to C is [tex]\sqrt{5}[/tex] and the hypotenuse is 2.
[tex]\frac{\sqrt{5} }{2} \approx0.75[/tex] is the sin of C.
The adjacent to C is 2 and the hypotenuse is 3.
[tex]\frac{2}{3} \approx 0.67[/tex] is the cos of C.
Hope this helped!
What is the solution to -5 + z = -12 A. z = -17 B. z = -7 C. z = 7 D. z = 17
Answer: -7
Step-by-step explanation:
. Emma wanted to make an origami fish for each of her 22 classmates. She takes 30 minutes to make one fish. How long will Emma take to make all the fish? A 320 minutes B 11 hours © 600 minutes D 660 hours
Answer:
11 hours
Step-by-step explanation:
50 minutes = 1 hour
30 minutes = 1/2 hour
She takes 1/2 per fish.
1/2 * 22 = 11
Answer: 11 hours
7 divided by 900 please help this question is annoying
Which list shows the order of the numbers from greatest to least? List 1: 2.3, 2.03, 2.5, 0.25 List 2: 0.25, 2.5, 2.03, 2.3 List 3: 2.03, 2.3, 2.5, 0.25 List 4: 2.5, 2.3, 2.03, 0.25
Answer:
4
Step-by-step explanation:
2.5, 2.3, 2.03, .25
I will give BRAINIEST to the next person who answers this!!
Answer:
Challenge #1:
Different examples:
2x+1=3x+2
4x+3=5x+4
3x+2=4x+3
Challenge #2:
Different examples:
2x+0=4x+1
3x+1=2x+5
6x+5=8x+6
Answer:
(-2x + 1 = 1x + 1) or (-4x + 2 = 2x + 2)
Step-by-step explanation:
what is the domain of the function shown in the graph below?
Answer type: interval, all real numbers, all values except one, all values except two
interval:
Answer:
All except one interval [-2,8]
Step-by-step explanation:
Notice that the function, wich an hyperbola, has a vertical asymptote in both -2 and 8 and there is nothing between this two values.
So we will exclude what's between them out of the domain.
simplify (45) - (+14)
Answer:
31
Step-by-step explanation:
(45) - (+14)
45 - 14 (Negative sign is distributed)
=31
The steepness or grade of a road is expressed as a percent. if a road rises 6feet for every 24 horizontal feet. What is the slope of the road? what percent grade is this ?
Answer:
25%
Step-by-step explanation:
The ratio of rise to run is ...
rise/run = 6 ft/24 ft = 1/4
Expressed as a percentage, this is ...
1/4 × 100% = 25%
_____
Comment on this grade
Interstate highways are limited to a 7% grade. Most local jurisdictions limit the grade of a road to somewhere between 12% and 15%.
Convert .23 Kiloliters to liters
what’s the answer?
Answer:
230 liters
Step-by-step explanation:
1000 liters is 1 kiloliter
Multiplying by the conversion factor
.23 kiloliters * 1000 liter/ 1 kiloliter= 230 liters
Answer:
= 230litres
Step-by-step explanation:
know that
1000liters makes 1 kilometer
if 1000liters make 1kilometer then we will multiply 0.23 by 1000litres
that is,
0.23 x 1000
= 230litres