Answer:
My answer will be (D) . A few thousand years
Explanation:
Carbon-14 is a radioactive isotope of carbon, containing 6 protons and 8 neutrons, that is present in the earth's atmosphere in extremely low concentrations.2
It is naturally produced in the atmosphere by cosmic rays (and also artificially by nuclear weapons), and continually decays via nuclear processes into stable nitrogen atoms.
Suppose we have a sample of a substance containing some carbon-14. Let m be the mass of carbon-14 in nanograms after t years. 3
It turns out that, if the sample is isolated, then m and t approximately 4 satisfy the differential equation
dmdt=−0.000121m.
Suppose our sample initially contains 100 nanograms of carbon-14. Let's investigate what happens to the sample over time.
First, we can solve the differential equation. Since m has a continuous decay rate of −0.000121, a general solution to the differential equation is
m(t)=Ce−0.000121t,
where C is a constant. Substituting the initial condition t=0, m=100 gives C=100, so
m(t)=100e−0.000121t.
With this formula, we can calculate the amount m of carbon-14 over the years.
Mass of carbon-14 in sample
t (years) m (ng to 4 decimal places)
0 100.0000
100 98.7973
1000 88.6034
2000 78.5056
5000 54.6074
10 000 29.8197
20 000 8.8922
Every year, the mass m of carbon-14 is multiplied by e−0.000121≈0.999879. After 100 years, 98.7973 nanograms still remain. After 1000 years, we still have 88.6034 nanograms. But after 5000 years, however, almost half of the carbon-14 has decayed.
Graph showing the decay of 100 nanograms of Carbon-14.
Detailed description
half-life of carbon-14
Example
How long does it take for precisely half of the carbon-14 in the sample to decay; that is, when does m=50? Give the answer to three significant figures.
Solution
The mass of carbon-14 in our sample is given by
m(t)=100e−0.000121t.
So we solve 50=100e−0.000121t, which gives e−0.000121t=12. Hence,
t=loge12−0.000121≈5730 years (to three significant figures).
The time period calculated in this example is called the half-life of carbon-14. In fact over any period of 5730 years, the amount of carbon-14 in an isolated sample will decay by half. This fact is used in radiocarbon dating to determine the age of fossils up to 60 000 years old. Roughly speaking, while an organism is alive, its interactions with its environment maintain a constant ratio of carbon-14 to carbon-12 in the organism; but after it dies, the carbon-14 is no longer replenished, and the ratio of carbon-14 to carbon-12 decays in a predictable way. (See Wikipedia Open new window for more on radiocarbon dating.)
Exercise 1
Explain why the mass of carbon-14 in the sample is given (approximately) by
m(t)=100(12)t5730,
and hence explain why the amount of carbon-14 in the sample decays by half over any period of 5730 years.
Half-life in general
In general, whenever a quantity x(t) obeys an exponential decay equation
x(t)=Cekt,
where the continuous decay rate k is negative, then the quantity x has a half-life T. After any time period of length T, the quantity x decreases by half. Let us see why.
As k is negative, the factor ekt decreases from 1 (at t=0) towards 0 (as t approaches ∞). Therefore there is a time t=T such that
ekT=12.
We now solve for T and obtain
kT=loge12=−loge2,
so
T=−1kloge2.
This T is the half-life. From time t=0 to time t=T, the factor ekt decreases from e0=1 to ekT=12, that is, decreases by half. Similarly, over any time period of length T, the term ekt decreases by half. 5
Note that, when k=−0.000121, we obtain T=5730, in agreement with our calculation for carbon-14.
Hope this work
If I'm wrong I'm sorry
If I'm right thank you (brainliest plz )
A 5-meter lever has a 4-meter long input arm. If an output force of 500 newtons is attached at one end of the
lever, how much input force must be applied to move the 500-newton output force?
Answer:
125N
Explanation:
500/4=125N
About how long does it take earth to make a make 1 revolution around the sun a a day be a week see a month d a year
which of the following correctly describes the hierarchy of genetic material within a cell
Answer: D- Each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA
Explanation:
A macromolecule is a large molecule that is made of many smaller units. Chromosomes are macromolecules that contain all of the genetic information in a cell. Chromosomes are each made of two smaller units called chromatids. Chromatids are each made up of molecules of DNA. Therefore, the correct description of the hierarchy of genetic material in a cell is that each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA. The structures become more and more microscopic as one moves down the hierarchy.
Write down the use of light pipe.???
Please kind sir/lady help me with my home work UvU
yes
Explanation:
the endorsment is successful because Jordan shoe is a imported brand
Why would a person who weighs 100 lbs. on Earth weigh significantly more on Ju-piter?
a. Jupiter has more gravitational force than Earth
b. Jupiter is farther away from the sun
c. Jupiter has no atmosphere
Answer:
Is a
Explanation:
Find the velocity of a runner who has a mass of 75 kg and 3,700 Joules of energy.
Answer:
125 joules
Explanation:
The velocity of the runner having a mass of 75 kg will be 9.93 m/s.
What is Kinetic energy of the body?
The energy of the body by virtue of its motion is called its kinetic energy.
Given is velocity of a runner who has a mass of 75 kg and 3,700 Joules of energy.
The kinetic energy of the body is given by the following formula -
KE = 1/2 mv².
Substituting the values -
3700 = 1/2 x 75 x v²
7400 = 75 x v²
v² = 7400/75
v² = 98.66
v = 9.93 m/s
Therefore, the velocity of the runner having a mass of 75 kg will be 9.93 m/s.
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The ______ or _______ of matter depends on how much the particles are moving, which depends on the amount of kinetic energy the particles possess.
Answer:
Temperature or thermal energy.
Explanation:
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Hence, the temperature or thermal energy of matter depends on how much the particles are moving, which depends on the amount of kinetic energy the particles possess.
A 4kg object is moving at 5 m/s . A 10-N force is applied in the direction of motion and if the object has a final velocity 10m /s. calculate the distance that the object moves
Answer:
Distance, S = 15m
Explanation:
Given the following data;
Mass = 4kg
Force = 10N
Initial velocity = 5m/s
Final velocity = 10m/s
To find the distance;
First of all, we would calculate the acceleration
Force = mass * acceleration
10 = 4*acceleration
Acceleration = 10/4
Acceleration = 2.5m/s²
Now to find the distance, we would use the third equation of motion.
[tex] V^{2} = U^{2} + 2aS [/tex]
Where;
V represents the final velocity measured in meter per seconds. U represents the initial velocity measured in meter per seconds. a represents acceleration measured in meters per seconds square.S represents the displacement measured in meters.
Substituting into the equation, we have;
10² = 5² + 2*2.5*S
100 = 25 + 5S
5S = 100 - 25
5S = 75
Distance, S = 75/5
Distance, S = 15m
What are 5 movements/skills that you are able to do because of your muscles?
Please help this is due today and I really need help.
One movement is walking. A skill we use is writing. Another movement is blinking. Another skill we use with muscles is typing. And finally, another skill we use muscles during is brushing your teeth.
True or False. The fulcrum of a first class lever is between the output force and an input force.
Answer:
True
Explanation:
A first-class lever is a lever in which the fulcrum is located between the input effort and the output load. In operation, a force is applied (by pulling or pushing) to a section of the bar, which causes the lever to swing about the fulcrum, overcoming the resistance force on the opposite side
what is hydraulic pressure
The total thrust, expressed in pounds or tons, that the hydraulic-feed mechanism on a drill can impose on a drill string; also, the pressure of the fluid within the hydraulic cylinders, generally expressed in pounds per square inch. Ref: Long.
Hydraulic pressure is the force imparted per unit area of a liquid on the surfaces which it has contact. Liquids are incompressible, and as such, when a load acts
a rock is an example of a solid because
Answer:
The key is that solids hold their shape and they don't flow like a liquid. A rock will always look like a rock unless something happens to it.
Solids can hold their shape because their molecules are tightly packed together.
Explanation:
Yes; it is a solid
What energy is this in the image
Answer:
chemical energy
Explanation:
Gives you energy to burn off
Answer:
yea what she said
Explanation:
what ever she said
I need some help with this table, i am unsure on how to answer it.
Answer:
I can't see it sorry I can't help
Answer:
i cant see it good could you resend it please thanks
what is evaporation
:D
Answer:
its when a liquid, prolly water, turns into a vapor !!
Explanation:
and nice pic uwu
A liquid turning into a gas is evaporation. It is how water gets from the surface of the Earth to the atmosphere.
Latent heat is a form of energy held in the evaporated water when it evaporates and cools.
Evaporation plays a significant role in the energy exchange that results in atmospheric motion, affecting weather and climate in the Earth-atmosphere system.
The particles with the highest kinetic energy are the first to evaporate from a liquid.
Most of the air's moisture evaporates from rivers, lakes, seas, and oceans. Water at the surface of the Earth evaporates into water vapor, which rises into the sky and forms clouds, which eventually release water back onto Earth as precipitation.
The resistance of 3A and 12V
An initially motionless test car is accelerated to 115 km/h in 8.58 s before striking a simulated deer. The car is in contact with the faux fawn for 0.815 s, after which the car is measured to be traveling at 60.0 km/h. What is the magnitude of the acceleration of the care before the collision? What is the magnitude of the average acceleration of the car during the collision?
Answer:
a) a = 3.72 m / s², b) a = -18.75 m / s²
Explanation:
a) Let's use kinematics to find the acceleration before the collision
v = v₀ + at
as part of rest the v₀ = 0
a = v / t
Let's reduce the magnitudes to the SI system
v = 115 km / h (1000 m / 1km) (1h / 3600s)
v = 31.94 m / s
v₂ = 60 km / h = 16.66 m / s
l
et's calculate
a = 31.94 / 8.58
a = 3.72 m / s²
b) For the operational average during the collision let's use the relationship between momentum and momentum
I = Δp
F Δt = m v_f - m v₀
F = [tex]\frac{m ( v_f - v_o)}{t}[/tex]
F = m [16.66 - 31.94] / 0.815
F = m (-18.75)
Having the force let's use Newton's second law
F = m a
-18.75 m = m a
a = -18.75 m / s²
Please help!! I'll name you brainliest!!
Answer:
11
Explanation:
the O at the end stands for oxygen and after that theres the number 11. that tells u how many oxygen atoms there are PLEASE AMRK BRAINLIEST ;C
Where would you expect to find volcanic mountain ranges and why?
Answer:
Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”
Explanation:
Volcanoes are found around tectonic plates because the convection currents move the plates. Where convection currents diverge near the Earth's crust, plates move apart. Where convection currents converge, plates move towards each other, plates converge and the plates move together, also known as ridge push, therefore mountains and volcanoes are formed
Hope this helps :)
Question 5 of 10
A dog pushes against the front door for 3 seconds with a force of 88 N. What
impulse has the
dog applied to the door?
A. 264 kg•m/s
O B. 77.2 kg•m/s
O C. 29.3 kg•m/s
OD. 128 kg•m/s
SLEMT
Answer:
265 Kg.m/sExplanation:
Impulse = Force × time
So 88× 3 =264!!
Answer:
264 kg*m/s
Explanation:
how could you use Newton's Second Law to study forces?
Answer:
F = ma or force is equal to mass times acceleration.
Explanation:
ANSWER ASAP THIS IS 6TH GRADE SCIENCE! GIVING BRAINLIEST FIVE STARS ANS A HEART!
A few days after a snowstorm, the roof of one house is still covered with snow, but the roof of another house is bare. What can you infer about the insulation under each roof? Explain.
Answer:
This shows the differences in the thermal tempretures and also how hot each home is.
Explanation:
Home this helps :)
Q2.
The information plate on a hairdrier is shown.
230 V
VSO Ha
800 W
(a) What is the power rating of the hairdrier?
Answer:
800W
Explanation:
Given the following data;
Voltage = 230 V
Model = VSO Ha
Power = 800 W
Power is calculated by the multiplication of voltage and current flowing through an electric circuit.
Mathematically, power is given by the formula;
Power = current * voltage
The S.I unit for power is Watts and it is a measure of the energy consumption of an electronic device.
the candle had 350 J of energy in the chemical store. As it burned, 250 J was transferred by lighting to the surrounding
Answer:
Efficiency = 71%
Explanation:
Given the following data:
Output energy = 250 Joules
Input energy = 350 Joules
To find efficiency;
[tex] Efficiency = \frac {Out-put \; energy}{In-put \; energy} * 100 [/tex]
Substituting into the equation, we have;
[tex] Efficiency = \frac {250}{350} * 100 [/tex]
[tex] Efficiency = 0.7143 * 100 [/tex]
Efficiency = 71.43 ≈ 71%
Therefore, the efficiency of the candle is 71 percent.
What does the formula "F=m xa" mean?
Answer:
Force = Mass x Acceleration
Explanation:
use the diagram to identify the four regions of the earthworm.
dorsal side:
ventral side:
anterior end:
posterior end:
here are some pictures
Answer:
Dorsal side:B
Ventral side:D
Anterior end:A
Posterior end:C
Explanation:
The four regions of the earthworm are, A is the anterior end,B is the dorsal side, C is the posterior end, and D is the ventral side.
What are earthworms?Earthworms are common soil dwellers who are both safe and useful. Earthworms help plants flourish by collapsing dead and decaying organic debris into rich humus soil.
They also aerate the soil and enhance flow by digging small canals and holes.
The four regions of the earthworm are;
A is the Anterior end
B is the Dorsal side
C is the Posterior end
D is the Ventral side
Hence all the regions are clearly defined with the help of digrame.
To learn more about the earthworms refer to the link;
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When a guitar string is plucked, sound waves, which are mechanical waves, transmit sound to your ears. What is the primary medium through which the sound waves travel?
The primary medium through which the sound waves travel is
Air.
What is a Wave?A wave is defined as a disturbance that travels through a
medium which transports energy from one place to another in
the process.
In a guitar, the vibration of the string sets the surrounding air
molecules into vibrational motion which thereby produces
sound heard.
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2. What kinds of statistics are used in sports? In a paragraph explain your answer with examples
from different sports.
Answer: Sports Illustrated noted that analytics in a sport such as a football is widely used to manage injury prevention. Basketball coaches make use of statistics such as field-goal attempts, effective field goal percentage, free throw attempts, and free throw percentages.
Explanation: BRAINLEST?
A police car is moving east at 20m/s towards a driver who is moving west at 25m/s. The police car emits a frequency of 900Hz. What frequency is detected by the driver? The speed of sound at the time of this occurrence was 343m/s.
Answer:
f = 2445 Hz
Explanation:
i did the quiz
The frequency that the driver (observer) detects is equal to 1008 Hz
Given the following data:
Observer velocity = 25.0 m/sFrequency of sound = 900 HzSource velocity = 20.0 m/s Speed of sound = 343 m/sTo calculate the frequency that the driver (observer) detects, we would apply Doppler's effect of sound waves:
Mathematically, Doppler's effect of sound waves is given by the formula:
[tex]F_o = \frac{V \;+ \;V_o}{V\; - \;V_s} F[/tex]
Where:
V is the speed of a sound wave.F is the actual frequency of sound.[tex]V_o[/tex] is the observer velocity.[tex]V_s[/tex] is the source velocity.[tex]F_o[/tex] is the observer frequency.Substituting the given parameters into the formula, we have;
[tex]F_o = \frac{343 \;+ \;20}{343\; - \;20} \times 900\\\\F_o = \frac{363}{323} \times 900\\\\F_o = 1.12 \times 900\\\\F_o =1008 \;Hz[/tex]
Driver (observer) frequency = 1008 Hz
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