Physics - Half life

89,482 results, page 6

Algebra 2

A radioactive substance decays at a rate of y = ae^-0.1483t, where t in in hours. Find the half-life of the substance. How do I solve this problem if I am only given the constant.

Pre-Calc

Tritium, a radioactive isotope of hydrogen, has a half-life of 12.4 years. Of an initial sample of 69 grams, how much will remain after 75 years?

Chemistry 212

The isotope sodium-22 has a half life of 2.60 years. What is the 1st order rate constant in inverse years? I am using the Ln (A/A0) = -Kt formula. Is that correct?

Physics

A sample contains 3.5×1019 radioactive atoms with a half life of 10000 years. How many atoms are expected to decay in the first second? After waiting 10000 years, how many atoms are expected to decay in the next second?

physics

Although most natural potassium nuclei are stable 39K (93.3%) or 41K (6.7%) nuclei, about 0.0117% are radioactive 40K nuclei, which have a half-life of 1.26 billion years. If you were worried about 40K radioactivity and wanted to wait for 97 % of the 40K in the environment to ...

chemistry 2

A voltaic cell is constructed with an Ag/Ag+ half-cell and a Pb/Pb2+ half-cell. Measurement shows that thesilver electrode is positive. -Write balanced half-reactions and the overall spontaneous reaction.

Alg2

Radioactive iodine is used to determine the health of the thyroid gland. It decays according to the equation y=ae -0.0856t where t is in days. Find the half-life of this substance. Round to the tenths place.

Alg2

Radioactive iodine is used to determine the health of the thyroid gland. It decays according to the equation y=ae -0.0856t where t is in days. Find the half-life of this substance. Round to the tenths place.

Chemistry

In solution, hypochlorite ion is known to decompose with a second-order rate law. If [ClO-]0 = 0.0570 M and k = 2.06x10-4 M-1·min-1, calculate the half-life for this reaction 2ClO-  2Cl- + O2.

Math

If a substance has a half life of 600 seconds. If a scientist begins with an initial amount of 1kg complete the following problems: create an exponential equation using proper variables?

chemistry

Radioactive waste is difficult to dispose of due to the long time periods needed before the radiation effectively disappears. The US protocol is to store the waste for 10 half-lives of the material after which the waste is no longer considered radioactive. After this time, ...

Physics

Could someone help explain this problem to me . . . Carbon 14 has a half-life of 5700 year, scientist use this fact to determine the age of things made of organic material. Suppose the average page of a book containing aprox. 0.5mg of Carbon 14 is put into a time capsule how ...

College Math

A certain man spent 10% of his life in childhood and 20% of his life as a young adult at which time he married his lovely bride. Five years later his son was born. His son lived to be half the age of his father when his father died. The man died ten years after his son died. ...

chemistry math

linen scrolls contain 80.9% of Carbon-14. how old are the scrolls if the half-life for deacy is 5.73X10^3?? plz tell me what type of equation to use.

Calculus

A certain radioactive material decays exponetially. The percent, P, of the material left after t years is given by P(t)= 100(1.2)^-t a)Determine the half life of the substance

chemistry

Consider the first order reaction A --> products where 25% of A disappears in 24 seconds. What is the half life of this reaction? ...i thought it would just be doubled but it isn't. i'd appreciate an explanation.

Alg2

A piece of wood discovered in an archaeological dig was found to have lost 62% of it's carbon-14. Carbon-14 has a half-life of 5630 years. Determine it's age.

Calculus

Radius decays at a rate of that is proportional to its mass, and has a half-life of 1590 years. If 20 g of radium is present initially, how long will it take for 90% of this mass to decay?

Math

The half-life of 234U, uranium-234, is 2.52 105 yr. If 97.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed? ? yr

algebra

The half-life of 234U, uranium-234, is 2.52 105 yr. If 97.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed

algebra

The half-life of 234U, uranium-234, is 2.52 105 yr. If 97.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

math

The half-life of 234U, uranium-234, is 2.52 105 yr. If 97.4% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

algebra

The half-life of plutonium-234 is 9 hours. If 40 milligrams is present now, how much will be present in 4 days? (Round your answer to three decimal places.)

algebra

The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.4% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

math

The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.3% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

algebra

The half-life of 234U, uranium-234, is 2.52 105 yr. If 97.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

College algebra

The radioactive element has a half-life of about 28 years and sometimes contaminates the soil. After 47 years, what percentage of a sample of the elements remain?

Chemistry 2

For the fist order reaction A <-> B, calculate the t1/2(half life) and k(rate constant) and also fill in the blanks. A-Concetration t-time 20 0 10 ? 5 40 sec 3 ? ? 500 sec t1/2=? k=?

Chemistry 2

For the fist order reaction A <-> B, calculate the t1/2(half life) and k(rate constant) and also fill in the blanks. A-Concetration t-time 20 0 10 ? 5 40 sec 3 ? ? 500 sec t1/2=? k=?

Chemistry

A first-order reaction has a half-life of 26.4 seconds. How long does it take for the concentration of the reactant in the reaction to fall to one-eighth of its initial value?

Math

A fossilized leaf contains 21% of its normal amount of carbon 14. How old is the fossil (to the nearest year)? Use 5600 years as the half-life of carbon 14.

Math

Suppose that the half-life of a substance is 250 yrs. .If there were initially 100 g of substance .How much will remain after 500 years??with solution please

physics

Calculate the maximum height using the initial speed, half-time, and angle. The initial speeed is 18m/s, half time is 1.8, and the angle is 75. And how is this written out to solve.

Chemistry

If 100.0 g of carbon-14 decays until only 25.0 g of carbon is left after 11,460 y, what is the half-life of carbon-14?

mechanics

The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using: A. a different material having a Young's modulus half that of steel B half the cross sectional area of the steel wire C half the length of steel wire D ...

physics help!!

A body at given uniform temperature of 300K and internal energy 8x10^6 J is split in two equal halves: a)Has any heat been exchanged b)What is the temperature of each half? c)What is internal energy of each half? K=Kelvin

adult education

How will your life experiences prove beneficial as you move through your degree program? Briefly describe two life experiences and illustrate how each will be useful as you pursue academic goals. How can you reject the negative influences in your life and benefit from the ...

Chemistry

I don't know the correct answer that's what i have to find. for the first part here is my work..... 6.2e-4/min=0.0372seconds half life: t_1/2=0.693/0.372s =18.6sec*1min/60sec=0.310min (which is not right!)

chemistry

follows first-order kinetics and has an activation energy of 244 kJ mol-1. At 684 K, k = 0.00000508 s-1. What is the half-life (min) for this reaction at 427 °C ? Round your answer to 3 significant figures. I really don't know what to do

Chemistry

The half-life for the first-order conversion of A to B is 56.5 hours. How long does it take for the concentration of A to decrease to 10.0% of its original amount? Our professor has given us the answer - 188hr but I am not entirely sure how he got it.

chemistry

A 7.500-mg sample of chromium-55 is analyzed after 14.0 min. and found to contain 0.469 mg of chromium-55. what is the half-life of chromium-55?

chemistry

a 7.500-mg sample of chromium-55 is analyzed after 14.0 min and found to contain 0.469 mg of chromium-55. what is the half-life of chromium-55

physics

The bunny is initially hopping east at 7 m/s when it first sees the fox. Over the next half second the bunny changes its velocity to west at 12 m/s and escapes. What was the bunny's average acceleration (magnitude and direction) during this half-second interval?

maths lit, geography, life science, history, life orientation, english, tswana

what can I do with my life with all this subjects that I studied?.

physics

The rubidium isotope 87Rb is a β emitter that has a half-life of 4.9 x 1010 y that decays into 87Sr. It is used to determine the age of rocks and fossils. Rocks containing the fossils of early animal have a ratio of 87Sr to 87Rb of 0.004. Assuming that there was no 87Sr ...

math

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 97.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

math

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 97.4% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

algebra

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 98.8% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

algebra

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 98.8% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

algebra

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 98.6% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

math

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 98.7% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed? yr

uncc

the half-life of 234U, uranium-234, is 2.52 x 10^5yr. If 98.5% of thee uranium in the original sample is present, what length of time (to the nearest thousand years) has elasped

pre algebra

The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.6% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?

ALGEBRA

The half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 98.3% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed? =

Physical Science- Help Please!

Suppose that you are given a 100 gram sample of a radioactive substance with a half-life of 32 days. How many grams will be left after 192 days?

MATH104

he half-life of 234U, uranium-234, is 2.52 multiplied by 105 yr. If 97.5% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed? yr

chemistry

Strontium-90 decays through the emission of beta particles. It has a half-life of 29 years. How long does it take for 80% of a sample of strontium-90 to decay? Show process of how you got this

college algebra

An isotope of lead, 201Pb, has a half-life of 8.4 hours. How many hours ago was there 40% more of the substance? (Round your answer to one decimal place.) ____hr

Probablity

The life time of a certain kind of batteries has a mean life of 400 hours and standard deviation as 45 hours. Assuming the distribution of life to be normal, find i) the percentage of batteries with a life time of atleast 470 hours. Ii) Out of 10000 batteries how many ...

physics

• If you use a cart with half the mass, you reach _______final speed. • If you use half the force, you reach ______ final speed. • If you push twice as long, you cover _______ distance during pushing. • If you use a cart with half the mass, you cover_______ distance ...

shakespeare

places in his life can it be where he was born what else conflicts in his life idk women in his life anne hathaway his wife men in his life can it be his fayher and the ppl he owrked with and his publisher children in his life susanna hamnet and judith mistakes he made idk ...

chemistry

You have a compound that is subject to decay. If you originally started with 80 g of the compound and you ended up with 5 grams 30 days later, what is the half-life of the compound?

abdul kabir

the half life of an element is 5 days. if we have 10gram of the element initially. what is the mass of the element after 5days and 10days

Intergrated physics and chemistry

A 52.0-kilogram skateboarder does a trick on a half-pipe. During the trick, he reaches a speed of 8.90 m/s. The radius of the half-pipe ramp is 3.00 meters. What is the minimum centripetal force necessary to keep the skater on the ramp?

physics

the mass density of a mixture of ethyl alcohol and water is 950kg/m^3. is the mixture mostly water, alcohol, or about half and half. What is your reasoning?

Physics

Calculate the maximum height using the initial speed, half-time, and angle. The initial speeed is 18m/s, half time is 1.8, and the angle is 75

History

What factors shaped the move from colonial, country life to modern, urban life? What was urban city life like during the rise of urbanization? How was it different or similar to modern urban life?

math

half of a gallon is a half gallon. half of a half gallon is a quart. half of a quart is a pint. half of a pint is a cup. a cup is what fraction of a quart? Is the answer 1/4?

mechanics of materials

The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using:which of the following is correct A. a different material having a Young's modulus half that of steel B half the cross sectional area of the steel wire C...

math

If a hen and a half can lay an egg and a half in a day and a half, then how much time is needed for three hens to lay three eggs?

physics

A car moves a distance of 200 km. It covers the first half of the distance at speed 40 km/h and second half of the distance by speed v. The average speed is 48 km/h. Find the value of v

AP Chem ---

Iron-59 has a half-life of 45.1 days. How old is an iron nail if the Fe-59 content is 25% that of a new sample of iron? Please show the calculating so I can learn to do it.

AP Chem ---

Iron-59 has a half-life of 45.1 days. How old is an iron nail if the Fe-59 content is 25% that of a new iron sample? Please show the calculating so I can learn to do it.

English

In “Wave,” Dale Wisely characterizes water as an element that a. gives life b. takes life c. gives and takes life d. is life

English

In “Wave,” Dale Wisely characterizes water as an element that a. gives life*** b. takes life c. gives and takes life d. is life

Calculus

Skeletal remains had lost 81% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.) yr

calculus

Skeletal remains had lost 70% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)

Math

Skeletal remains had lost 84% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)

Chemistry

I need help with the following problem: A fabric remnant from a burial site had a 14 C:12 C ratio of 0.838 of the original value. How old is the fabric? (half-life of 14 C = 5370 years)

math

How long will it take a given quantity of carbon-14 to lose 99.9% of its radioactivity if the half life is 5730 years? The formula I have been given is Q=ae^rt This is using log and ln functions.

Algebra 2

A 14 gram sample of a substance that's used to preserve fruit and vegetables has a k-value of 0.1092. Find the substance's half-life, in days. Round your answer to the nearest tenth.

MATHS

experiments show that radium disintegrates at a rate proportional to the amount of radium present at the moment . if half life is 1590 years what percentage will disappear in one year?

MATHS

please help me ...Experiments show that radium at rate proportional to the amount of radium present at the moment . if half life is 1590 years what percentage will disappear in one year ??

Physics

A thin, uniform rod is hinged at its midpoint. To begin with, one half of the rod is bent upward and is perpendicular to the other half. This bent object is rotating at an angular velocity of 6.8 rad/s about an axis that is perpendicular to the left end of the rod and parallel...

physics

A thin, uniform rod is hinged at its midpoint. To begin with, one-half of the rod is bent upward and is perpendicular to the other half. This bent object is rotating at an angular velocity of 7.1 rad/s about an axis that is perpendicular to the left end of the rod and parallel...

mechanics of materials

Select the correct answer.The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using: A. A different material having a Young's modulus half that of steel B half the cross sectional area of the steel wire C half ...

physics

We have to do a lab in physics where we research and write on real life applications of momentum, the guidelines we have are Research Assignment: Application of Momentum in Real-Life Situations Task: Choose any real-life situation where the concept of momentum is involved and ...

Physics 2

Calculate the maximum height using the initial speed, half-time, and angle. The initial speeed is 9.8m/s, half time is 1.8, and the angle is 75.

math

If a hen and a half lay an egg and a half in a day and a half, how many hens are needed to lay a dozen eggs in one day?

Ethics

Which of the following answers to the meaning of life did Tolstoy hold prior to his change of heart and mind? my answer is A a. Life has no meaning, and we must embrace that fact. b. Life's meaning is to provide comfort for oneself and one's family. c. Life's meaning is to ...

Chemistry

a compound decomposes with half life of 8seconds and is independent of concentration.how much time is consumed to convert the concentration of one sixteenth of its initial concentration?

Chemistry 2

For a second order reaction A <--> B, calculate the t1/2 (half life) and the k(constant) and also fill in the blanks. A (concentration) t(time) 20 0 sec 10 ? 5 40 sec 3 ? ? 200 sec t1/2=? k=?

Chemistry

Iron -59 has a half -life of 45.1 days. How old is an iron nail if the Fe-59 content is 25% that of a new sample of iron? Show all calculations leading to a solution.

physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young module total length of bar is 2 when bar ...

physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young module total length of bar is 2 when bar ...

physics

bar subjected to gravity load (two segments) the bar in the fig has constant cross sectional area A .the top half of the bar is made of material with mass density and youngs module, the bottom half of the bar made of density and young module total length of bar is 2 when bar ...

Physics

The lower half of an inclined plane is rough the upper half being smooth a particle is allowed to slide from the top and is brought to rest by friction just as it reaches the bottom, find the ratio of the force of friction to the weight of the particle intermes of the ...

Physics

The lower half of an inclined plane is rough the upper half being smooth a particle is allowed to slide from the top and is brought to rest by friction just as it reaches the bottom, find the ratio of the force of friction to the weight of the particle intermes of the ...

chemistry

Use the following steps to balance the redox reaction below: Mg + Au+ Mg2+ + Au -Write the oxidation and reduction half-reactions. Make sure each half-reaction is balanced for number of atoms and charge. -Multiply each half-reaction by the correct number, in order to balance ...

chemistry

use the nuclear decay equation to find out how much a 7mg sample of iodine 128 remains after 116 minutes if the half life of this isotope is 25 minutes.

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