A sample of polonium-210 was left for 414 days.
BA
After this time it had a mass of 1.45 x 10^-4 g
The half-life of polonium-210 is 138 days.
Calculate the initial mass of the sample

Answers

Answer 1

Answer:

PO(1) = PO(0) / 2       1 refers to 1 half life of PO(0)

PO(2) = PO(1) / 2 = P(0) / 4        amount of PO left after 2 half-lives

PO(3) = PO(2) / 2 = PO(0) / 8     amount of PO left after 3 half-lives

414 da / 138 da = 3       3 half-lives pass in 414 da

PO(0) = 8 PO(3) = 8 * 1.45E-4 g = 1.16E-3 g = .00116 g  after 414 days        


Related Questions

Power of an electric motor is 1 h.p. what does it mean ?​

Answers

Answer: HP = Horse Power.

Explanation: it is the unit given to tell the motor's particular power and 1hp = 746 watts.

Question 2

You can make the puck travel in complex ways by placing a set of charges around on the field. So, here’s your game challenge:
Arrange sources charge around to propel the puck from its starting position into the goal. That’s pretty easy for a straight shot; you just put a negative charge behind the goal. But what if there are barriers along the way? This is a real test of your physical understanding, including Newton’s laws of motion and electrostatic forces. Game’s on!

Part A

On the control bar, check the Trace and Field boxes. The game has three Difficulty levels. Start with Difficulty level one and arrange source charges to get the puck into the goal. Once you’ve made a score at any level, increase the Difficulty level. Take a screen capture of two of your most difficult goals and paste them here. At least one of these should be at Difficulty level 2 or 3.

Answers

Answer:

A. The electric field lines point outward and the black puck moves backwards. From this I can see that I can't put the red charge in front of the black puck because it will go away from the goal.

B. The electric field lines point inward and the black puck moves forwards and backwards. The conclusion I made from this was the blue charge by itself will not be able to get into the goal.

C.The puck moves faster when the mass increases and moves slower when the mass decreases. The more mass, the more force that is applied to the puck.

D.  The relationship between the speed of the black puck and its distance from the blue charge is when the puck is further away from the blue charge, the slower the puck moves away from it.

Explanation:

Brainlest if this helped!

2. In a race, if a runner starts and stops at the same position, what is their
displacement? *

Answers

Answer:

It is the same

Explanation:

I Jsut know

why does the energy of characteristic x rays tend to increase for heavier elements?

Answers

The energy of characteristic x rays tend to increase for heavier elements

because the charge of the nucleus increases.

X ray is a form of an electromagnetic spectrum and the energy is directly

proportional to the charge of the nucleus. This implies that an increase in

the nucleus charge will lead to a corresponding increase in x ray energy

and vice versa.

X rays energy is also usually more in heavier elements than when

compared to lighter elements

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An amateur astronomer has just discovered a dwarf planet in an orbit past Pluto. Choose the best unit of measure to describe how far out in the solar system it is from the Sun.

Answers

the answer is B) Light years

The brightest light detected from the star Antares has a frequency of about 3 x 10^(14) Hz. What is the wavelength of this light?

Answers

Taking into account the definition of wavelength, frecuency and propagation speed, the wavelength of a light with a frequency of 3×10¹⁴ Hz is 1×10⁻⁶ m.

First of all, wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).

On the other side, frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

Finally, the propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave disturbance propagates along its displacement.

The propagation speed relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:

v = f * λ

All electromagnetic waves propagate in a vacuum at a constant speed of 3x 10⁸ m/s, the speed of light.

In this case, you know:

v=3x 10⁸ m/s f= 3×10¹⁴ Hz λ= ?

Replacing:

3x 10⁸ m/s= 3×10¹⁴Hz× λ

Solving:

λ= 3x 10⁸ m/s ÷ 3×10¹⁴Hz

λ=1×10⁻⁶ m

In summary, the wavelength of a light with a frequency of 3×10¹⁴ Hz is 1×10⁻⁶ m.

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brainly.com/question/2232652?referrer=searchResults brainly.com/question/7321084?referrer=searchResults brainly.com/question/14946166?referrer=searchResults

A circular coil consisting of 500 turns with an area of 6.0x10-4 m 2 is rotating in a uniform magnetic field. At the start, the normal to the coil is perpendicular to the magnetic field. After 15s, the normal to the coil is 60⸰ with the magnetic field. The average induced emf is -0.058V. What is the magnitude of the magnetic field?

Answers

The magnitude of the magnetic field in the coil is 21.65 T.

The given parameters;

number of turns, N = 500 turnsarea of the coil, A = [tex]6\times 10^{-4} \ m^2[/tex]change in time, t = 15 s

The induced emf in the coil is determined by applying Faradays law;

[tex]emf =N \frac{d\phi }{dt} \\\\emf = N ( \frac{\phi _2 - \phi_1}{t} )\\\\emf= N(\frac{BAsin\ 60 - BAsin\ 90}{t} )\\\\emf = NBA(\frac{sin60 - sn90}{t} )\\\\-0.058 = 500(6\times 10^{-4})\times B\times (\frac{0.866 - 1}{15} )\\\\-0.058 = -0.00268B\\\\B = \frac{0.058}{0.00268} \\\\B = 21.65 \ T[/tex]

Thus, the magnitude of the magnetic field in the coil is 21.65 T.

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Plzzzz help meeeeee plzzz

Answers

hun I wish I can help you but I have the same problem here!! sorry


1 Loudness and pitch are two important properties of a musical sound.
a If a musician plays a softer note, which property has been changed,
loudness or pitch?
b If the musician makes the note lower, which property has been
changed, loudness or pitch?

Answers

pitch loudness is with you lower you tone & get quite

An object has an acceleration of 6.0 m/s/s. If the NetForce was tripled and the mass was halved, then the new acceleration would be _____ m/s/s

Answers

Hi there!

We know that:

∑F = ma

If you tripled the net force and halved the mass:

3F = 1/2ma

Rearrange for 'a':

3F × 2 = ma

6F = ma

Thus, the new acceleration would be 6 times the original, or 36 m/s².

Thirty Joules of energy are transferred out of a system. The energy is lost through heat, mechanical, and electrical energy. If mechanical energy took up 10 J and electrical energy took up 5 J, how many Joules were lost through heat energy?

OPTIONS

5 J



15 J



30 J



45 J

Answers

Answer:

its 15 J i belive

Explanation:

1+1 =?
2+2=?
3+3=?

1+1 =?
2+2=?
3+3=?

Answers

Answer:

here is your answer

1+1=2

2+2=4

4+4=8

PLEASE ANSWER ASAP
A 5 kg bowling ball traveling at 2 m/s hits a motionless 10 kg bowling ball. If the smaller ball bounces back at a speed of -1 m/s, what will be the speed of the larger ball after the collision?

Answers

Hi there!

Recall the conservation of momentum:

m1v1 + m2v2 = m1v1' + m2v2'

Let m1 = 5 kg ball and m2 = 10 kg ball

Since m2 is at rest, we can rewrite:

m1v1 = m1v1' + m2v2'

Plug in the given values:

5(2) = 5(-1) + 10v2'

Solve for v2':

10 = -5 + 10v2'

15 = 10v2'

15/10 = 1.5 m/s

Given ↷

m1 =5kgm2=10( since it's at rest)v1=2m/sv2=0(since it's at rest)v1' = -1To find ↷the speed of the larger ball after the collisionSolution↷

We know that,

m1v1 + m2v2 = m1v1' + m2v2'

5 x 2 + 0 = 5 x -1 + 10 x v2'

10= -5 +10 x v2'

15 = 10 x v2'

v2' = 15/10

v2' = 1.5 m/s

hence , the speed of the larger ball after the collision will 1.5m/s

Glucose typically enters the cell through which mechanisms

Answers

Answer:

facilitated diffusion

....................................

Answers

Answer:

yeah

Explanation:

Helllo, hope you are doing well :)

Which is true of the intensity of sound?

Answers

Answer:

c.

Explanation:

The gravitational field strength on Mars is 3. 7 N/kg. Kai has a mass of 55 kg. What would Kai weigh on Mars? Give your answer to 1 decimal place.

Answers

Hi there!

Weight = mass × acceleration due to gravity (or gravitational field strength)

We can write this as:

W = mg

Plug in the given values:

W = 55 × 3.7

W = 203.5 N

Can anyone help out with this question?
I'll mark as brainliest
Thankyou. ​

Answers

Answer:

p=I×B

Explanation:

If a current 'I' flows through a given element in your circuit, losing voltage 'V' in the process, then the power 'P' dissipated by that circuit element is the product of that current and voltage.

The student investigates how the resistance of a thermistor varies with temperature. The student has a power supply, a thermistor, an ammeter, a voltmeter and some connecting leads. Describe an investigation the student could carry out to measure the resistance of a thermistor between –10 °C and 70 °C.

Your answer should include:

1. Any other apparatus the student will need
2. The measurements to be taken
3. How the data should be processed.

(This question is worth 6 marks on my assignment so I just really want to get down the best possible answer for it.)

Answers

The characteristics of the thermistors allow to design an experiment to analyze the dependence of resistance with temperature;

      1) We set up the circuit

      2) We look for the current of the circuit and we keep it fixed.

      3) We look for the thermistor resistances for each temperature.

      4) Plot Resistance versus Temperature.

A Thermitor is an element whose resistance changes with temperature, for example a platinum resistance.

An experiment that we can carry out to measure is to set up the attached circuit where we have:

A DC power supply. A resistor to control the maximum current in the circuit and avoid thermal problems in the thermistor. A thermistor. A thermometer placed next to the thermistor. A source of heat under the thermistor under a glass with ice and water, but without affecting the other elements of the circuit.

Let's start by looking for the current in the circuit.

In thermistors, the resistance for room temperature is given, so if we measure the voltage across the fixed resistor, we can shrink the voltage across the thermistor.

         

           [tex]V_{source} = V_R + V_{therm} \\V_{therm} = V_{source} - V_R \\ i = \frac{V_{therm} }{R_{therm}}[/tex]

This current remains fixed, since the fixed resistance is greater than the resistance of the thermistor throughout the range.

Second step.

Now we can change the temperature that is measured in the thermometer, for each temperature the voltage in the fixed resistance is measured, the resistance in the thermistor is calculated.

        [tex]R_{therm} = \frac{V_{source} - V_R}{i}[/tex]  

Third step.

We end with a graph of resistance versus temperature of the curve obtained, it is possible to understand the behavior of the resistance of the thermistor with temperature.

In conclusion with the characteristics of thermistors we can design an experiment to analyze the dependence of resistance with temperature:

      1) We set up the circuit

      2) We look for the current of the circuit and we keep it fixed.

      3) We look for the thermistor resistances for each temperature.

      4) Plot Resistance versus Temperature.

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If two stars are in a binary system with a combined mass of 5.5 solar masses and an orbital period of 12 years, what is the average distance between the two stars

Answers

The average distance between the two stars is 792 light years

Let the mass of the first star be [tex]m_1[/tex]

Let the mass of the second star be [tex]m_2[/tex]

The combined mass of the two stars, [tex]m_1+m_2=5.5[/tex] solar masses

The orbital period of the stars, P = 12 years

Average distance between the two stars, D = ?

The average distance between the two stars can be calculated using Kepler's equation

[tex]D=(m_1+m_2)P^2[/tex]

Substitute [tex]m_1+m_2=5.5[/tex] and P = 12 into the formula [tex]D=(m_1+m_2)P^2[/tex]

[tex]D=5.5(12^2)[/tex]

D = 5.5(144)

D = 792 light years

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The diagram shows what happened in the Rutherford and Marsden scattering experiment. Complete this sentence: The particle shown in red will come straight back from the foil because it is __________ by the charge in the gold nucleus.

Answers

From Rutherford  and Marsden scattering experiment, we can conclude that the particle shown in red will come straight back from the foil because it is deflected by the charge in the gold nucleus.

Rutherford proposed Planetary model atom, which visualized an atom to consists of a positively charged heavy core called the nucleus around which negatively charged electrons circle in orbits much as planets move round the sun

Thus, from Rutherford  and Marsden scattering experiment, we can conclude that the particle shown in red will come straight back from the foil because it is deflected by the charge in the gold nucleus.

Learn more here:https://brainly.com/question/24263685

the answer is reflected or u can say repelled

Arthur (mass 79 kg) and Violet (mass 50 kg) are trying to play on a seesaw. If Violet sits 4 m from the fulcrum, at what distance from the fulcrum should Arthur sit

Answers

Hi there!

There are two torques acting on the system:

τ (Arthur) = RW = R(790N)

τ (Violet) = RW = 4(500N) = 2000N

∑τ = 0 = τ(Violet) - τ(Arthur)

Thus:

τ(Violet) = τ(Arthur)

2000 = 790R

R ≈ 2.53m

Which of the following are for vector directione?
A Outside 45 degrees
G 35 degrees north of east
D 35 degrees inside

Answers

Answer:
C. outside 45 degrees
Step-by-step explanation:
C. outside 45 degrees
because it can be any point or direction outside 45 degrees

A person drops two objects from the same height. One object weighs 15 N, and the other weighs 10 N. How does the mass of the objects relate to the force of gravity on them? A. The 10 N object has the same mass as the 15 N object. B. The 10 N object has more mass than the 15 N object. C. The 15 N object has twice the mass of the 10 N object. D. The 15 N object has more mass than the 10 N object. SUR​

Answers

Answer:

Your answer would be D :)

Explanation:

An object with a higher mass will always fall faster due to gravity acting upon it. 15 N is more massive than the 10 N object, so statement D is correct.

if there is a gravitational force between all objects, why do we not feel or observe it?

Answers

We do not feel the gravitational forces from objects other than the Earth because they are weak.

Answer:

We do. It's just way too small compared to the force between the objects we're observing and the earth. It's like looking inside a room with an elephant and a grain of rice. The rice is there, it's just too small compared to the room and the elephant inside for you to notice it. Or, if you ever traveled on a plane, you can easily see the towns, or the roads, but not the single people walking the street.

A body is accelerated constantly. What is the form of the graph? A. cubic. B. inverse. C. linear. D. quadratic.​

Answers

Answer:

D is the correct answer for this question.

Explanation:

I had done this already

What is its time interval between the release of the ball and the time it reaches its maximum height? Its initial vertical speed is 9 m/s and the acceleration of gravity is 9.8 m/s 2 . Neglect air resistance.

Answers

Answer:

The time to reach max height is    h = 1/2 g t^2  

The time to fall is the same as that for an equivalent rise

m g h = 1/2 m v^2       KE vs PE

Here:   (Vf - VI) / g = t = -9  / -9.8 = .92 s

A helicopter travelling at a velocity of 15 m/s [W] accelerates uniformly at a rate of 7.0 m/s2 [E] for 4.0 s. What is the helicopter’s final velocity?

Answers

If we take West to be the negative direction, then the initial velocity is -15 m/s and the acceleration (which points East) is +7.0 m/s².

After t = 4.0 s, the helicopter's velocity is

-15 m/s + (7.0 m/s²) (4.0 s) = +13 m/s

or 13 m/s [E].

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

Calculate the relative molecular of calcium carbonate

* as following method*

Answers

Answer:

100.22

Explanation:

Have a great day!

An object weights 1000N on the earth’s surface. [ g=10N/Kg]
Calculate its mass

Answers

Answer: An object weights 1000N on the earth's surface. ... Calculate its mass ... strength is 10 N/kg how many newtons does a 30kg object weigh.

Explanation:

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