Answer:
If you take A0 to be the initial sample of iodine-131, you will be left with. 12⋅A0=A02→ ... m24 hours=12.5%mo=12.5⋅10−2⋅mo
Explanation:
is that what u look for
Sample I-131 decays to 12.5% in 24.21 days.
What is half-life?Half-life, in radioactivity, is the amount of time needed for half of a radioactive sample's atomic nuclei to decay (change spontaneously into other nuclear species by emitting particles and energy), or, alternatively, the amount of time needed for a radioactive material's rate of disintegrations per second to decrease by half.
Give parameters:
Half-life of the radioactive element I-131:T = 8.07 day
It decays to 12.5% means it decays to 1/8.
According to definition of half-life,
The radioactive element I-131 decays to half in 8.07 days.
So, the radioactive element I-131 decays to 1/8 in 3×8.07 days = 24.21 days.
Hence, the radioactive element I-131 decays to12.5% in 24.21 days.
Learn more about half-life here:
https://brainly.com/question/24710827
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I need help with the questions when it says what is the topic and rest
Directions: Summarize the main ideas of this lesson by answering the question below.
How might a person acquire a fear of or aversion to something even though it has no negative effect
on him or her?
Answer:
Explanation:
Trypophobia is a fear or disgust of closely-packed holes. People who have it feel queasy when looking at surfaces that have small holes gathered close together.A person may start by imagining what they fear, then looking at pictures of the fear object, and then finally being near or even touching the source of their anxiety. In the case of trypophobia, a person with symptoms may start by simply closing his eyes and imagining something such as a honeycomb or seed poThey can help you find the root of the fear and manage your symptoms. Last medically reviewed on July 20, 2017 Medically reviewed by Timothy J. Legg, Ph.D., CRNP — Written by Annamarya Scaccia ...
Which of the following does not illustrate a complete circuit?
Answer:
I think A
Explanation:
because it dosn't have enough tools
the fall of a body on the earth's surface cannot be a complete free fall why ?
Explanation:
because the boy has larger surface area due to which he offers the larger air resistance which decreases the acceleration so, he will fall towards the earth's surface approximately with constant velocity.
An object is falling from a height of d and reaches a final velocity of vf. Calculate velocity when the object has fallen a distance d/2.
Answer:
The final velocity, [tex]v_{f}[/tex], is gd.
Explanation:
The condition here is a free falling object. Thus from the third equation of motion under free fall, we have;
[tex]v_{f}[/tex] = [tex]v_{i}[/tex] + 2gs
where [tex]v_{f}[/tex] is the final velocity of the object, [tex]v_{i}[/tex] is the initial velocity of the object, g is the gravitational force and s is the height.
Since the object falls from a height of d, then [tex]v_{i}[/tex] = 0 m/s, and s = d.
So that;
[tex]v_{f}[/tex] = 0 + 2gd
= 2gd
[tex]v_{f}[/tex] = 2gd
When the distance is [tex]\frac{d}{2}[/tex], [tex]v_{i}[/tex] = 0 m/s.
Then;
[tex]v_{f}[/tex] = 2g[tex]\frac{d}{2}[/tex]
[tex]v_{f}[/tex] = g x d
When the object falls through the height [tex]\frac{d}{2}[/tex], then the final velocity is gd.
help plz The sum of all chemical reactions that take place within an organism is known as ______________. *
Answer:
Metabolism
Explanation:
metabolism is the sum of all chemical reactions that take place within an organism
Answer:
Metabolism
Explanation:
Read the following dream interpretation and answer the question that follows.
"I suspect that the patient's dream of being chased originates from his unresolved feelings of guilt during childhood."
What perspective of dream interpretation is being offered?
A. Freudian
B. activation-synthesis
C. Jungian
D. motivation
Answer:
Freudian
Explanation:
Answer:
Freudian
Explanation:
The force of attraction between two oppositely charged pith is 5mx 10 to the -6th power newtons. If the charge on the two is 6.7 x 10 to the -9th power coulombs what is the distance between the two charges
Answer:
0.28 m
Explanation:
The following data were obtained from the question:
Force (F) = 5×10¯⁶ N
Charge 1 (q₁) = 6.7×10¯⁹ C
Charge 2 (q₂) = 6.7×10¯⁹ C
Electrical constant (K) = 9×10⁹ Nm²C¯²
Distance apart (r) =?
Thus, the distance between the two charges can be obtained as follow:
F = Kq₁q₂/r²
5×10¯⁶ = 9×10⁹ × 6.7×10¯⁹ × 6.7×10¯⁹/r²
5×10¯⁶ = 4.0401×10¯⁷ / r²
Cross multiply
5×10¯⁶ × r² = 4.0401×10¯⁷
Divide both side by 5×10¯⁶
r² = 4.0401×10¯⁷ / 5×10¯⁶
Take the square root of both side
r = √(4.0401×10¯⁷ / 5×10¯⁶)
r = 0.28 m
Therefore, the distance between the two charges is 0.28 m
Do you think the inner planets should be explored or should the money be spent on other things? Justify your opinion.
Answer:
yes i think that inner planets should be explored because if we ever find new life or are able to live there then i think its worth takeing a risk.
Explanation:
A train travels with a speed of 115km/hr. How much time does it take to cover a distance of 470km.
It would take approximately 4 hours for the train to cover a distance of 470km.
4 hours 5 minutes 13.04 seconds
A merry go round exerts a force of 1000 N on a rider on the
outer ring of animals when it takes 15 seconds to make a
complete revolution. If the person weighs 750 N, the radius
of the circle he is making is m. Round your answer to
the nearest tenth.
Answer:
The radius of the circle made by the person on the merry go round is 74.55 meters
Explanation:
The given parameters are;
The force the merry go round exerts on the rider = 1000 N
The time it takes the merry go round to make one complete revolution = 15 seconds
The weight of the person = 750 N
The radius of the circle made by the person on the merry go round = r
We have;
[tex]F_c = \dfrac{m \cdot v^2}{r} = m \cdot \omega ^2 \cdot r[/tex]
Where;
m = The mass of the person
v = The velocity of the person
[tex]F_c[/tex] = The centrifugal force acting on the person = 1,000 N
r = The radius of the circle made by the person on the merry go round
ω = Angular velocity = 2·π/15 rad/s
We have;
The mass of the person = The weight/(The acceleration due to gravity, g)
∴ The mass of the person = 750/9.81 ≈ 76.45 kg
By substituting the calculated and known values into the equation for the centripetal force, we have;
[tex]F_c[/tex] = m × ω² × r
1000 = 76.45 × (2·π/15)² × r
r = 1000/(76.45 × (2·π/15)²) = 74.55 m
The radius of the circle made by the person on the merry go round = r = 74.55 m.
Calculate the kinetic energy of a 50 kg cart moving at a speed of 18.6 m/s.
Answer:
8649 J
Explanation:
KE = 1/2mv^2
1/2(50)(18.6)^2
1/2(50)(345.96) = 8649 J
Yuna is writing an opinion piece about her Schools lunch menu which text structure would best Express her ideas check all that apply
Answer:
Cause and effect, problem and solution, order of importance, comparison and contrast.
Explanation:
A 1500 kg car has an applied forward force of 5000 N and experiences an air resistance of 1250 N. What is the car's acceleration?
Answer:
[tex]2.33\ m/s^2[/tex]
Explanation:
Net Force
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
Fn = m.a
Where a is the acceleration of the object. The net force is the sum of the individual vector forces applied to the object.
The m=1500 Kg car has two horizontal forces applied: the forward force of 5000 N that causes the movement and the air resistance force of 1250 N that opposes motion.
The net force is Fn = 5000 N - 1500 N = 3500 N
To find the acceleration, we solve the equation for a:
[tex]\displaystyle a=\frac{Fn}{m}[/tex]
[tex]\displaystyle a=\frac{3500}{1500}[/tex]
[tex]\boxed{a = 2.33\ m/s^2}[/tex]
The car's acceleration is [tex]a = 2.33\ m/s^2[/tex]
Which of the following is NOT one of the essential components of an exercise program?
Answer:
i dont know dude but ask someone who is in your grade lol
Explanation:
The air is an example of a gas in a gas solution. True or false
WILL MARK BRAINLY!! QUICK HELP PLEASE!
A 40.0 kg rocket produces a
764 N upwards force ("thrust").
What is the net force acting on
the rocket?
Answer:
372Explanation:(40.0)×(9.8)=392
764N-392=372
You are standing on a moving bus, facing forward, and you suddenly fall forward. You can imply form this that the bus’s
A 4812 kg boulder sits on top of a 203 m cliff. What is its PE?
Answer:
9572992.8 JExplanation:
The potential energy of a body can be found by using the formula
PE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 9.8 m/s²
From the question we have
PE = 4812 × 9.8 × 203
We have the final answer as
9572992.8 JHope this helps you
Which one of the following is not a member of the solar family: (a) Morning Star (b) Evening Star (c) Pole Star (d) Tailed Star plzzz answer this...
Answer:
Tailed star
Explanation:
Tailed star
a small balloon containing baking soda has a mass of 4 grams. A student adds 10 ml. of vinegar
to a 100 gram glass bottle. The student stretches the opening of the balloon over the mouth of
the bottle, mixing the baking soda and vinegar inside the bottle. Once the balloon is inflated, the
student finds the mass of the balloon, bottle, and their contents to be 116 grams. What was the
mass of the vinegar originally in the bottle
F.10g G.12g J.16g
Answer:
10 grams
Explanation:
I took a test with this question earlier.
26. For this table of data, which column is the independent variable?
radius of circle (m) area of circle (m2)
3.4
36.317
4.5
63.617
4.6
66.476
6.2
120.763
7.6
181.458
7.7
186.265
8.6
232.352
9.7
295.592
area of circle
o
radius of circle
O
None of these is correct.
Answer:
radius of a circle is measured by an instrument, so it is the independent variable
Explanation:
The independent variable corresponds to the magnitude controlled by the experimenter and in general can be measured by an instrument.
The dependent variable is the variable used to perform the calculations, obtained from a mathematical transformation of the independent variable.
The radius of a circle is measured by an instrument, so it is the independent variable and the area is calculated by
A = π r²
Therefore the area corresponds to the dependent variable
Why do you think it is colder during the winter than the summer?
Answer:
As the earth travels around the sun during the year it maintains this tilt. Because of this tilt, in the summer we (north of the equator) are slanted more directly towards the sun so it's hotter. In the winter, we're slanted away so the sun's rays are less direct, making it colder.
will you help me please
Answer: True
Explanation: It's true because the definition of a Command economy states that it's an economy in which production, investment, prices, and incomes are determined CENTERALLY by a GOVERNMENT.How long will it take an object traveling at 7 m/s to reach a distance of 26 meters
Answer:
3 hours 71 minutes
Explanation:
As because Speed= distance/time taken
so time taken= 3.71
A 50 kg circus worker stands on a merry go round platform. If the worker's acceleration is 2.5 m/s2, what is her centripetal force?
F = ma
= 50kg × 2.5 m/s²
= 125 N
Answer : 125N
Explanation :
F = Force (N)
m = mass (kg)
a = acceleration (m/s²)
If you could change one property of a substance ( solid, liquid, and gas) you have to use in your daily life, what would it be and why?
Please hurry
I will give you BRAINLIEST!!!!!!
And pleaseee write 5 sentences why??
Answer
Soap into a liquid
Explanation:
Which best compares radiation and conduction?
A. Both transfer thermal energy from warm objects to cooler objects.
B. Both can transfer energy through empty space.
C. Both transfer thermal energy by electromagnetic waves.
D. Both involve the transfer of energy through direct contact.
And also who likes Rick and Morty OwO
Answer:
A
Explanation:
g. Write the merits and demerits of ultraviolet rays.
Answer:
UV rays aid in the production of Vitamin D. But it can also give you cancer.
Explanation:
i am a scientist
the diagram shows the apparent motion of the sun across the sky?
Answer:
The earth rotates west to east
Explanation:
Considering that the sun doesn't really move and the earth is rotating around the sun, and it is moving from east to west with us (the earth) facing it in which means the earth rotates around the sun west to east!