3. Sodium-24 has a half-life of 15 hours. If a sample of sodium-24 has an
original activity of 800 Bq, what will
its activity be after:
i) 15 hours?
ii) 30 hours?
iii) 45 hours?
iv) 60 hours?

Answers

Answer 1

Answer:

See explanation

Explanation:

From the formula;

0.693/t1/2 = 2.303/t log (Ao/A)

t1/2 = half life of Sodium-24

Ao = initial activity of Sodium-24

A= activity of Sodium-24 at time = t

So,

0.693/15 = 2.303/15 log (800/A)

0.0462 = 0.1535  log (800/A)

0.0462/0.1535 =  log (800/A)

0.3 = log (800/A)

Antilog(0.3) =  (800/A)

1.995 =  (800/A)

A = 800/1.995

A = 401 Bq

ii) 0.693/15 = 2.303/30 log (800/A)

0.0462 = 0.0768 log (800/A)

0.0462/0.0768 =  log (800/A)

0.6 =  log (800/A)

Antilog (0.6) =  (800/A)

3.98 =  (800/A)

A = 800/3.98

A = 201 Bq

iii)

0.693/15 = 2.303/45 log (800/A)

0.0462 = 0.0512  log (800/A)

0.0462/0.0512  =  log (800/A)

0.9 = log (800/A)

Antilog (0.9) =  (800/A)

7.94 = (800/A)

A = 800/7.94

A= 100.8 Bq

iv)

0.693/15 = 2.303/60 log (800/A)

0.0462 = 0.038 log (800/A)

0.0462/0.038 = log (800/A)

1.216 = log (800/A)

Antilog(1.216) = (800/A)

16.44 = (800/A)

A = 800/16.44

A = 48.66 Bq


Related Questions

What are the properties of fourth matter plasma?

Answers

[tex] \\ [/tex]

Like gases, plasmas have no fixed shape or volume, and are less dense than solids or liquids. But unlike ordinary gases, plasmas are made up of atoms in which some or all of the electrons have been stripped away and positively charged nuclei, called ions, roam freely.

[tex] \\ [/tex]

Hope It Helps!

Stored energy due to vertical position is known as
Elastic Potential energy
Vibrational energy
Kinetic energy
O Gravitational Potential energy
1
2
3
4
5

Answers

Answer: gravitational potential energy

Explanation:

The Sun is spherical due to
gravitation
Earth and Moon circling it.
Earth circling it.
none of the above

Answers

Answer:

gravitation

good luck, hope this helps :)

gravitation hope this helps

State four factors affecting thermal conductivity​

Answers

Answer:

∙ Temperature

∙ Concentration of electrolyte

∙ Nature of the electrolyte added

∙ Nature of solvent and its viscosity

Explanation:

Two forces are exerted on an object in the vertical direction: a 20 N force downward and a 10 N force upward. The mass of the object is 25 kg. (1) What are some possibilities about the motion of this object? (2) Represent the motion of the object with a force diagram and a motion diagram.

Answers

Answer:

They are equal.

Explanation:

Two long parallel wires 20 cm apart carry currents of 5.0 A and 8.0 A in the between the two wires where the magnetic field is zero?
a. yes, midway between the wires
b. yes, 12 cm from the 5-A wire
c. yes, 7.7 cm from the 5-A wire
d. no

Answers

Answer:

c. yes, 7.7 cm from the 5-A wire

Explanation:

Given;

distance between the two wires, r = 20 cm = 0.2 m

first current, I₁ = 5.0 A

second current, I₂ = 8.0 A

The magnetic field due to the two wires occurs in different directions and it can be zero at this region.

Let x be the distance from 5 A wire where the magnetic field is zero.

[tex]B = \frac{\mu_o}{2\pi} [\frac{I_1}{x} -\frac{I_2}{r-x} ] = 0\\\\ \frac{\mu_o}{2\pi} [\frac{I_1}{x} -\frac{I_2}{r-x} ] = 0\\\\ \frac{\mu_o}{2\pi} [\frac{5}{x} -\frac{8}{0.2-x} ] = 0\\\\\frac{5}{x} -\frac{8}{0.2-x} = 0\\\\\frac{5}{x} = \frac{8}{0.2-x}\\\\5(0.2-x) = 8x\\\\1 -5x = 8x\\\\1 = 5x \ + \ 8x\\\\1 = 13x\\\\x = \frac{1}{13} \\\\x = 0.077 \ m\\\\x = 7.7 \ cm[/tex]

Therefore, the correct option is c. yes, 7.7 cm from the 5-A wire

FIND THE DISTANCE BETWEEN TWO GIVEN POINTS.

1. S (5, -1) and T (5, 7)


Answers

Answer:

8 units

Explanation:

The answer is 8 units hope this helps

Q:- EXPLAIN WHY THE PLANETS DO NOT TWINKLE. ​

Answers

stars twinkle because they are so far away from earth that ,even through large telescopes, they appear only as pinpoints.

planets shine more stedily because they are closer to earth and so appear as pinpoints but as tiny disks in our sky.

Why is the total solar eclipse important for scientists? explain​

Answers

Answer:

hello

Explanation:

For scientists, they offer a unique opportunity to study aspects of the sun like its corona, the layer of plasma surrounding the star. ... By studying the inner regions of the corona that we can generally only see and photograph well during a total solar eclipse, scientists can learn more about how weather works in space.

have a nice day

hope it helps

byee

Answer:

For scientists,they offer a unique opportunity to study aspects of the sun like it's Corona, the layer of plasma surrounding the star......By studying the inner regions of the Corona that we can generally only see and photograph well during a total solar eclipse, scientists can learn more about how weather works in space

If you have a 0.125 kg lead piece at
20.0°C, how much heat must you
add to melt it? (Remember, you
must warm it to its melting point
first.)
Material
Lead
Melt Pt (°C)
327
L (1/kg)
2.32.104
Boil Pt (°C) Lv (1/kg)
1750 8.59.105
c (1/(kg*c)
128
(Unit = J)

Answers

Answer:

7,812 J

Explanation:

Using the relation:

Q = mcΔθ

Q = quantity of heat

C = specific heat capacity of lead

Δθ = temperature change (T2 - T1)

M = mass of substance

Q = mass * specific heat * Δθ

Q = 0.125kg * 128 * (327 – 20)

Q = 0.125 * 128 * 307

Q = 4912 J

For melting:

Q = mass * Hf

0.125 * (2.32 * 10^4)

= 2,900 J

Total = 4,912 J + 2,900 J = 7,812 J

Name the nutrients required for the body​

Answers

Answer:

Explanation:

Water.

Carbohydrates.

Protein-Amino acids.

Fat.

Vitamins.

Minerals.

Omega-3 fatty acids.

A factory emits pollutants at a rate of 25 g/s. The factory is located between two mountain ranges resulting in an effective valley width of 5000 m. The height of the ceiling due to atmospheric conditions is 1000 m. During the fall and spring, a breeze that travels at a velocity of 4 m/s flows through the valley. Fortunately, the breeze coming in contains no pollutants. Based on the information given, the steady state concentration of pollutants in the valley, in micrograms per cubic meter is.

Answers

Answer:

[tex]1.25\ \mu\text{g/m}^3[/tex]

Explanation:

v = Velocity of the breeze = 4 m/s

w = Width of the valley = 5000 m

h = Height of the valley = 1000 m

Volumetric flow rate is given by

[tex]\dot{V}=vwh\\\Rightarrow \dot{V}=4\times 5000\times 1000\\\Rightarrow \dot{V}=2\times10^{7}\ \text{m}^3/\text{s}[/tex]

[tex]\dot{m}[/tex] = Mass flow rate of pollutant = 25 g/s = [tex]25\times 10^6\ \mu\text{g/s}[/tex]

Concentration is given by

[tex]C=\dfrac{\dot{m}}{\dot{V}}\\\Rightarrow C=\dfrac{25\times 10^6}{2\times 10^7}\\\Rightarrow C=1.25\ \mu\text{g/m}^3[/tex]

The steady state concentration of pollutants in the valley, is [tex]1.25\ \mu\text{g/m}^3[/tex].

your "A" never changes, while your "Y" changes depending on strength of gravity. is it mass or weight? ​

Answers

Answer:

A - mass. B - Weight

Explanation:

This is because weight varies with the strength of gravity. Mass is just the amount of matter in an object

What is the correct description of any change in a position farther to the left of zero?
1- negative displacement
2- negative position

Answers

Answer:

negative displacement

Explanation:

cause its written farther that means its doin movement

A 2[kg] rock and a 4[kg] rock are lifted to a height of 10[m].
How much PE does each rock have?

Answers

Answer:

See below

Explanation:

Potential Energy = mgh

      for 2 rock = 2 * 9.81 * 10 = 196.2 j

      for 4 rock = 4 * 9.81 * 10 = 392.4 j

Which pair of labels is correct? A: Maximum kinetic energy C: Maximum gravitational potential energy B: Maximum kinetic energy D: Maximum gravitational potential energy A: Maximum gravitational potential energy C: Maximum kinetic energy B: Maximum gravitational potential energy D: Maximum kinetic energy

Answers

Maximum kinetic enerygy

Answer: C. A:Maximum gravitational potential energy C: Maximum kinetic energy

Explanation:

The loaded car of a roller coaster has mass M = 320 kg. It goes over the highest hill with a speed v of 21.4 m/s. The radius of curvature R of the hill is [01] m. (a) What is the force (N) that the track must exert on the car? (positive is up) (b) What must be the force (N) that the car exerts on a 61 kg passenger?

Answers

This question is incomplete, the complete question is;

The loaded car of a roller coaster has mass M = 320 kg. It goes over the highest hill with a speed v of 21.4 m/s. The radius of curvature R of the hill is 15.8 m.

(a) What is the force (N) that the track must exert on the car? (positive is up)

(b) What must be the force (N) that the car exerts on a 61 kg passenger?

Answer:

a) the force (N) that the track must exert on the car is -6139.14 N

b) the force (N) that the car exerts on a 61 kg passenger is -1170.27 N

Explanation:

Given the data in the question;

Let N represent the force that the track must exerted on the car

Net force on the car Fnet = Mg + N

so

M × a = Mg + N

N = Ma - Mg

N = Ma - M(v²/R)

we substitute

N = (320kg × 9.8m/s²) - ( 320 × ((21.4m/s)² / 15.8 m) )

N = 3136 - ( 320 × 28.9848 )

N = 3136 - 9275.136

N = -6139.14 N

Therefore, the force (N) that the track must exert on the car is -6139.14 N

b) What must be the force (N) that the car exerts on a 61 kg passenger?

Let N represent the force that the car exerts on 61kg passengers

so

Net force of passengers Fnet = mg + N

Ma = Mg + N

N = Ma - Mg

N = Ma - M(v²/R)

N = (61kg × 9.8m/s²) - ( 61 × ((21.4m/s)² / 15.8 m) )

N = 597.8 - ( 61 × 28.9848)

N = 597.8 - 1768.0728

N = -1170.27 N

Therefore, the force (N) that the car exerts on a 61 kg passenger is -1170.27 N

The centripetal force of the track on the car moving in the circular path is [tex]1.465 \times 10^6 \ N[/tex].

The force (N) that the car exerts on a 61 kg passenger is 597.8 N.

Centripetal force of the track

The centripetal force of the track on the car moving in the circular path is calculated as follows;

[tex]F_c = \frac{mv^2}{r}\\\\ F_c = \frac{320 \times 21.4^2}{0.1} \\\\F_c = 1.465 \times 10^6 \ N[/tex]

Normal force of the passenger

The force (N) that the car exerts on a 61 kg passenger is equal to the force the passenger exerts on the car based on Newton's third law of motion.

F = mg

F = 61 x 9.8

F = 597.8 N

Learn more about centripetal force here: https://brainly.com/question/20905151

8+10÷5(5×4+2)=?
it ıs said that this question was very diffıcult
can you slove?​

Answers

Answer:

220 bastanyan sagot ko yawa

Answer: 220
Use PEMDAS
5*4=20+2=22 so 8+10/5(22)
10/5=2
8+2=10
10(22) or 10*22 is 220

Need help only in part C!
An electric space heater draws 15.0 A from a 120-V source. It is operated, on the average, for 5.0 h each day. a. How much power does the heater use ? b. How much energy in kWh does it consume in 30 days? C. AED 0.30 per kWh , how much does it cost to operate the heater for 30 days ?

Answers

Answer:

A. 1800 Watt

B. 10.8 KW/h

C. AED 3.24

Explanation:

A. Determination of the power.

Voltage (V) = 120 V

Current (I) = 15 A

Power (P) =?

P = IV

P = 15 × 120

P = 1800 Watt

B. Determination of the energy consumption in KW/h for 30 days

We'll begin by converting 1800 Watt to kilowatt. This can be obtained as follow:

1000 W = 1 KW

Therefore,

1800 W = 1800 W × 1 KW / 1000 W

1800 W = 1.8 KW

Next, we shall determine the energy consumption per day. This can be obtained as follow:

Power (P) = 1.8 KW

Time (t) = 5 hour per day

Energy (E) =?

E = P /t

E = 1.8 / 5

E = 0.36 KW/h per day.

Finally, we shall determine the energy consumption in 30 days. This can be obtained as follow:

1 day = 0.36 KW/h

Therefore,

30 days = 30 × 0.36 KW/h

30 days = 10.8 KW/h

Thus, the energy consumption in 30 days is 10.8 KW/h

C. Determination of the cost of operation in 30 days.

1 KW/h = AED 0.30

Therefore,

10.8 KW/h = 10.8 KW/h × AED 0.3 / 1 KW/h

10.8 KW/h = AED 3.24

Thus, the cost of operation in 30 days is AED 3.24

Answer:

1800 W

Explanation:

PLEASE ANSWER. I WILL MAKE YOU THE BEST ANSWER BRAINLIEST. I PROMISE.
Anna weighs 132 lb. Determine her mass in kilograms using the conversion 1 kg equal 2.2 lb. Use this mass to answer this question.

calculate Anna's weight on the Moon. (G = 1.6 m / S2) must include a unit with your answer ​

Answers

1). If 2.2 lb actually = 1 kg, then

(132lb) x (1 kg/2.2lb) = 60 kg.

(Sadly, 2.2 lb doesn't " = " 1 kg. The explanation, unfortunately, is beyond the scope of this discussion.)

2). Weight = (mass) x (gravity)

Moon weight = (60 kg)x(1.6 m/s^2)

Moon weight = 96 Newtons

During sexual reproduction, each parent contributes

Answers

Answer:

each parents contributes the dad gives the seed and the mom gives the egg

Explanation:

and then you are born

A beam of light, incident on a flat water surface, reflects from the mirror-like surface so that the angle of incidence equals the angle of reflection. The water has waves. Would individual light beams obey the law of reflection in this case?

Answers

Answer:

a protractor

Explanation:

because protractors measure angles

what is the distance of truck and travel if it moves 7MS for 20 seconds

Answers

It would have to be 7MSx 20.... if it is moving 7 meters a second than that would mean that you have to multiply that by 20...

7x20=140M

A meteorologist who has been analyzing weather data from the last fifty years found evidence of climate change. An ecologist has been studying deposits of pollen from the last fifty years to track the types of plants that grew in certain regions. She has also found evidence of climate change. What does this imply about science?
A. Meteorology and ecology are the same type of science.
B. When scientific disciplines overlap, researchers should choose new topics.
C. Different scientific disciplines can be used to investigate similar questions.
D. There should be fewer sciences, as they seem to answer the same questions.
Explain

Answers

Answer:

Probably (C), but don't forget the argument that:

Roses are red, and roses are flowers; therefore all flowers are red.

a. If we increase the wind velocity, the maximum vertical dispersal height and rate of diffusion will decrease____.
b. If we increase the humidity, the maximum vertical dispersal height will ___________increase____ after 24 hours.
c. If we increase the lapse rate, the maximum vertical dispersal height of the pollutants will ____________________.

Answers

Answer:

a.If we increase the wind velocity, the maximum vertical dispersal height will decrease, while the rate of diffusion will increase

b.If we increase the humidity, the maximum vertical dispersal height will increase after 24 hours.

c.If we increase the lapse rate, the maximum vertical dispersal height of the pollutants will increase

Explanation:

a.If we increase the wind velocity, the maximum vertical dispersal height will decrease, while the rate of diffusion will increase

b.If we increase the humidity, the maximum vertical dispersal height will increase after 24 hours.

c.If we increase the lapse rate, the maximum vertical dispersal height of the pollutants will increase

Answer:

a decrease

b increase

c increase

Write an article to explain the process that occurs when matter is heated, or cooled. How does matter change its physical state between solid, liquid, and gas? Provide a real-life example. Also, describe the properties of the three main states of matter.

Answers

Answer:

when matter is heated or cooled it melts or freezes for at least the atoms do

Explanation:

for example take water when you heat it up the water molecules melt producing vapor water vapor and when you freeze it or cool it down it turns into liquid or turned into a solid by turning into ice. the three main properties of matter are gas liquid and solid and if we put water into these three different categories it turns into water vapor as gas liquid water as liquid and Ice as a solid

hope this helps

walking dancing and even some household chores are? ​

Answers

Answer:

Actions

Explanation:

if u mean what are these called then it's actions

Answer: Regular Physical Activity

Explanation:

explain the advantage of polarized sunglasses over normal tinted sunglass​

Answers

Answer:

Explanation:

Polarized lenses improve vision by making colors appear deeper and bolder and eliminating uncomfortable and often dangerous glare, as well as filtering harmful ultraviolet light

What are two benefits of scientists using a diagram to model the water cycle?
A. It can be used to show how the parts of the cycle relate to one
another.
B. It can be used to show as much detail ahis present in the actual
water cycle.
c. Only a few factors in the water cycle can be shown on the
diagram
D. It can show changes that occur in many different parts of Earth at
the same time.

Answers

Answer:

Options A. and D. are correct.

Explanation:

The water cycle shows the continuous movement of water within the Earth and atmosphere.

The two benefits of scientists using a diagram to model the water cycle are as follows:

It can be used to show how the parts of the cycle relate to one  another.

It can show changes that occur in many different parts of Earth at  the same time.

Options A. and D. are correct.

Consider a uniformly charged sphere of total charge Q and radius R centered at the origin. We want to find the electric field inside the sphere (r

Answers

Answer:

Hello your question is incomplete attached below is the complete question

answer :

Total charge enclosed within the sphere : [tex]\frac{q_{r1} }{4\pi e_{0}R^3 } . r[/tex]

Total charge enclosed outside the sphere : [tex]\frac{q}{4\pi e_{0}r^2 } .r[/tex]

Explanation:

Given data:

Total charge of a uniformly charged sphere = Q

radius = R

first step : find the electric field inside and outside the uniformly charged sphere

2nd step : determine the total charge enclosed within and outside the sphere

make a sketch of the uniformly charged sphere

Attached below is a detailed solution

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