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3 years ago

RIGHT ANSWER GETS BRAINLIEST+5 STARS.

Physics

2 answers:

gogolik [260]3 years ago

8 0

Answer:

B) the decay rates of radioactive uranium and lead

Explanation:

As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.

Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time

So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate

now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.

so by the formula

$t = \frac{1}{\lambda}ln(\frac{N_0}{N})$

we can find the age of the sample

insens350 [35]3 years ago

5 0

Answer:

B) the decay rates of radioactive uranium and lead

Explanation:

The radioactive decay is modeled using an exponential function with an essential parameter, namely the decay rate. The two rates (for urianium and lead) allow her to determine the number of years that passed since the time the zirconium was formed.

You might be interested in

An airplane is heading due south at a speed of 690 km/h . A) If a wind begins blowing from the southwest at a speed of 90 km/h (

Afina-wow [57]

Answer:a) 629,5851 km/h in magnitude b)629,5851 km/h at 84,2 degrees from east pointing south direction or in vector form 626,6396 km/h south + 63,6396km/h east. c) 16,5 km NE of the desired position

Explanation:

Since the plane is flying south at 690 km/h and the wind is blowing at assumed constant speed of 90 km/h from SW, we get a triangle relation where

see fig 1

Then we can decompose those 90 km/h into vectors, one north and one east, both of the same magnitude, since the angle is 45 degrees with respect to the east, that is direction norhteast or NE, then

90 km/h NE= 63,6396 km/h north + 63,6396 km/h east,

this because we have an isosceles triangle, then the cathetus length is

hypotenuse/ $\sqrt{2}$

using Pythagoras, here the hypotenuse is 90, then the cathetus are of length

90/ $\sqrt{2}$ km/h= 63,6396 km/h.

Now the total speed of the plane is

690km/h south + 63,6396 km/h north +63,6396 km/h east,

this is 626,3604 km/h south + 63,6396 km/h east, here north is as if we had -south.

then using again Pythagoras we get the magnitude of the total speed it is

$\sqrt{626,3604 ^2+63,6396^2} km/h=629,5851km/h$ ,

the direction is calculated with respect to the south using trigonometry, we know the

sin x= cathetus opposed / hypotenuse,

then

x= $sin^{-1}'frac{63,6396}{629,5851}$ =5,801 degrees from South as reference (0 degrees) in East direction or as usual 84,2 degrees from east pointing south or in vector form

626,6396 km/h south + 63,6396km/h east.

Finally since the detour is caused by the west speed component plus the slow down caused by the north component of the wind speed, we get

Xdetour{east}= 63,6396 km/h* (11 min* h)/(60 min)=11,6672 km=Xdetour{north} ,

since 11 min=11/60 hours=0.1833 hours.

Then the total detour from the expected position, the one it should have without the influence of the wind, we get

Xdetour=[/tex]\sqrt{2* 11,6672x^{2} }[/tex] = 16,5km at 45 degrees from east pointing north

The situation is sketched as follows see fig 2

4 0

4 years ago

Assume you have four fins each with a mass of 8.0 grams what is the total weight if these four fins

irinina [24]

I do believe the answer would be 2.0 each fin because 2.0+2.0=4.0 do that twice you should get 8.0 let me know if that is correct please hope I helped

6 0

4 years ago

A ball rolls along the floor with a constant velocity of 2.3 m/s. How far will it travel after 15 seconds.

marissa [1.9K]

Answer:

0. 153m

Explanation:

displacement= velocity/ time

S = 2.3 m/s / 15s

S = 0. 153m

5 0

4 years ago

Using an example, explain how small atoms are.

Aliun [14]

Unlike a ball, an atom doesn't have a fixed radius. The radius of an atom can only be found by measuring the distance between the nuclei of two touching atoms, and then halving that distance... Does that answer your question?

4 0

3 years ago

(EXPLAIN) why is mercury thermometer a element? if you explain correctly you will get brainliest

shutvik [7]

Mercury looks pretty, in its shiny, fast-moving liquid form, but don't touch! It can be extremely poisonous to humans.

The symbol Hg that mercury is known by comes from its Greek name, hydrargyrum, which means "liquid silver" — to reflect its shiny surface. The element is also known as quicksilver for its mobility. Named after the fastest-moving planet in the solar system, mercury has been known to humanity for ages. In fact, evidence of its use has been found in China, India and Egypt, and traces of mercury were found in 3,500-year-old Egyptian tombs.

Mercury is a very toxic element. It can enter the body through an open wound or by inhaling or ingesting it. It can then cause damage to nerves, the liver and the kidney, as well as a number of other symptoms.

Despite its toxic qualities, mercury can still be useful to us. The element conducts electricity and is used in electrical switches of thermostats and certain types of doze alarm-type alarm clocks, according to the College of Natural Resources at the University of California, Berkeley (CNR) "The place where people probably see it most commonly is in the new light bulbs — the compact fluorescent light bulbs," where mercury vapor is one of the chemicals used, said Daniel King, an associate professor of chemistry at Drexel University.

Due to its high density and compactness, mercury is also used to make thermometers, barometers and other scientific instruments, according to the Jefferson Lab. However, for safety reasons, consumer use of mercury in thermometers has become less common over the years, as digital thermometers have been introduced. In 2008, 13 states introduced laws that limit the manufacture, sale and/or distribution of mercury fever thermometers: California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, Washington, the Environmental Protection Agency reports.

Just the facts

Atomic number (number of protons in the nucleus): 80

Atomic symbol (on the Periodic Table of Elements): Hg

Atomic weight (average mass of the atom): 200.59

Density: 13.5336 grams per cubic centimeter

Phase at room temperature: Liquid

Melting point: minus 37.8 degrees Fahrenheit (minus 38.83 degrees Celsius)

Boiling point: 674.11 F (356.73 C)

Number of isotopes (atoms of the same element with a different number of neutrons): 34. Number of stable isotopes: 7

Most common isotope: 202Hg (29.9 percent natural abundance)

Mercury is typically found in the form of its common ore cinnabar — mercury sulfite — and can rarely be found on its own. To extract pure mercury, the ore is ground up and heated to the temperature of about 1,076 degrees F (580 degrees Celsius) with oxygen present in the process. Mercury vapor escapes from the ores and sulfur dioxide is removed, according to CNR. The metal is condensed and washed with nitric acid to purify it, and then distilled.

Mercury can form alloys with gold, silver, zinc and cadmium, which are called amalgams. Through those amalgams, mercury can be used to extract gold from rocks. When mercury comes into contact with gold, the gold dissolves into the mercury and then the two are separated, with the mercury being distilled off.

Mercury also forms compounds with other elements. Interestingly, one of such compounds — mercury nitrate — played a role in the coining of the term "mad as a hatter."

"Mercury was actually used in the making of hats from animal pelts," King said. In the 18th century people used the mercury nitrate compound to clean the pelts before they turned them into hats.

"And they discovered that a large percentage of the people who were working with those chemicals ended up suffering from brain damage," he said. "So the term 'mad as a hatter' actually comes from exposure to mercury."

3 0

3 years ago