Answer:
a) A Helium nucleus with two protons and one neutron
b) 0.324 of the original amount
Explanation:
a) When Tritium decays, the nucleus emits an electron and an antineutrino, which then changes it from a Triton with one proton and two neutrons, to a Helium nucleus with two protons and one neutron.
The decay constant for the decay of Tritium is gotten from
[tex]t_{1/2}[/tex] = 0.693/k
where
[tex]t_{1/2}[/tex] is the half life = 12.3 yrs
k is the decay constant = ?
substituting, we have
12.3 = 0.693/k
k = 0.693/12.3 = 0.0563
The fraction that will remain after 20 years can be calculated from
[tex]N[/tex] = [tex]N_{0} e^{-kt}[/tex]
where
[tex]N[/tex] is the final remaining amount of Tritium after 20 years
[tex]N_{0}[/tex] is the original amount of Tritium
k is the decay constant = 0.0563
t is the time = 20 years
Equation can be re-written as
[tex]N/N_{0}[/tex] = [tex]e^{-kt}[/tex]
where
[tex]N/N_{0}[/tex] is the fraction of the tritium that will be remaining after 20 years.
substituting values, we have
[tex]N/N_{0}[/tex] = [tex]e^{-0.0563 * 20}[/tex]
[tex]N/N_{0}[/tex] = [tex]e^{-1.126}[/tex]
[tex]N/N_{0}[/tex] = 0.324 of the original amount
A person pulls a box across a floor. Which is the correct analysis of the situation? A. The box moves forward because the person pulls forward slightly harder on the box than the box pulls backward on the person. B. Because action always equals reaction, the person cannot pull the box. The box pulls backward just as hard as the person pulls forward, so there is no motion. C. The person gets the box to move by giving it a tug during which the force on the box is momentarily greater than the force exerted by the box on the person. D. The person's force on the box is as strong as the force of the force of the box on the person, but the frictional force on the person is forward and large while the backward frictional force on the box is small. E. The person can pull the box forward only if it weights more that the box.
Answer:
D. The person's force on the box is as strong as the force of the box on the person, but the frictional force on the person is forward and large while the backward frictional force on the box is small.
Explanation:
When a bag is pulled, then it involves a person’s force on the box meaning there is an opposite force which is equal to the force of the box on the person.
When the box is pulled, there is a forward frictional force on the person which is big when compared to the backward frictional force which is small. This positive difference is responsible for the movement of the box.
g ) (62.44 pts.) Explain why a maximum or a minimum of occurs exactly when an inflection point occurs for
Answer:
we approach a maximum or minimum the values of the ordinate are closer and closer and when passing this point the values change their trend
Explanation:
The reason for this process occurs because as we approach a maximum or minimum the values of the ordinate are closer and closer and when passing this point the values change their trend if they were rising, they begin to fall and if they were falling they begin to rise. Therefore the maximum point is a point of inflection of the curve since its trend changes.
Another way of looking at this process is that mathematically the point where there is a maximum or a minimum corresponds to the point where the first derivative is equal to zero, this is the slope of the line is horizontal, so the points before after correspond to values with slope of different sign.
If someone told you that they traveled 50 km east, are they describing the distance they traveled or their displacement? How do you know? *
Answer:
they are describing their displacement since displacement is nothing but distance along with the direction of motion
Is lava a matter if yes how if not how
Answer:
Yes, lava is a liquid, that cools into rock, which is a solid.
We all know that punching a solid wall can badly hurt your hands. Using Newton's Third Law, how can you explain this happening? a. According to Newton's Third Law, the force you put into the wall with your punch causes the wall to put that same force back onto your hand. b. According to Newton's Second Law, the harder you hit the wall, the more you need to exert yourself and your hand to do so, which damages your hand c. According to Newton's First Law, you cannot stop your hand once your cause it to start moving, thus your hand will be damaged by hitting the wall because you can't stop it in time d. Newton's Laws cannot explain this
The answer is B
Explanation:
Every action has an equal reaction. If you punch a wall, the wall is going to exert the wall with exert the same amount of force back towards your hand, causing your hand to hurt.
Answer:
a. According to Newton's Third Law, the force you put into the wall with your punch causes the wall to put the same force back onto your hand.
Explanation:
I got it correct.
Have you donated blood ? If so describe your experience. If not, explain whether you would or would not donate blood and why.
A fishing pole is an example of a compound machine. What simple machines are used to make up this compound machine?
Answer:
Corkscrew, bicycle, scissors
Explanation:
they are made from many simple machine's
Answer:
compound meachiun include bicycles, cars, scissors, and fising rods with reels.
The highest that George can suck water up a very long straw is 2.0 m . (This is a typical value.) Part APart complete What is the lowest pressure that he can maintain in his mouth
Answer:
81,725 N/m^2
Explanation:
Given the following :
Height of water = 2m
Density of water = 1000kg/m^3
Atmospheric pressure (Pat) = 101325 N/m^2
Lowest pressure (Pl) can be obtained thus ;
Pat - Pl = density × height × acceleration due to gravity
101325 - Pl = 1000 × 2 × 9.8
101325 - Pl = 19600
101325 - 19600 = Pl
Lowest pressure (Pl) = 81,725 N/m^2
81,725 N/m^2 = (81,725/101325) atm
= 0.8065630 = 0.8065 atm
28.25 mL, three signicant digits
Answer:3) variable affinities (stickiness) for something it is running past. Physical ... -measurement number (significant digits) unit (such as inches) -Significant ... Mass 1 oz. 28.25 g. Relations Between English and Metric Units Mass 1 dram. 1.772 g ... -graduated cylinder has an error of about 1% (± 0.1 mL in 10 mL). -Volumetric
Explanation:
Answer:
1. 28.25 mL, three significant digits.
2. 54.074 mL, three significant digits
3. 600.006 km, four significant digits
4. 1356 kg + 4.2 kg + 19.891 kg
Explanation:
Two point sources produce waves of the same wavelength that are in phase. At a point midway between the sources, what kind of interference would be observed?
Answer:
Constructive interference
Explanation:
Because the path difference between them is zero owing to the fact that they are in phase
Determine the nuclear radius (in fm) for each of the following nuclei.
a) 126C
b) 147N
c) 6027Co
d) 20882Pb
Answer:
(a) 2.75 fm
(b) 2.89 fm
(c) 4.70 fm
(d) 7.12 fm
Explanation:
For a given element, the radius r of its nuclei is given by;
r = r₀[tex]A^{(1/3)}[/tex]
Where;
A = Atomic mass of the element
r₀ = 1.2 x 10⁻¹⁵m = 1.2fm
Now let's solve for the given elements
(a) ¹²₆C
Carbon element => This has an atomic mass number of 12
Therefore its radius is given by;
r = 1.2 x [tex]12^{1/3}[/tex]
r = 1.2 x 2.29
r = 2.75 fm
(b) ¹⁴₇N
Nitrogen element => This has an atomic mass number of 14
Therefore its radius is given by;
r = 1.2 x [tex]14^{1/3}[/tex]
r = 1.2 x 2.41
r = 2.89 fm
(c) ⁶⁰₂₇Co
Cobalt element => This has an atomic mass number of 60
Therefore its radius is given by;
r = 1.2 x [tex]60^{1/3}[/tex]
r = 1.2 x 3.92
r = 4.70 fm
(d) ²⁰⁸₈₂Pb
Lead element => This has an atomic mass number of 208
Therefore its radius is given by;
r = 1.2 x [tex]208^{1/3}[/tex]
r = 1.2 x 5.93
r = 7.12 fm
(a) A runner starts from rest and in 2 s reaches a speed of 10 m/s. If we assume that the speed changed at a constant rate (constant net force), what was the average speed during this 2 s interval
Answer:
Average speed is 5 m/s
Explanation:
The initial speed = 0 m/s (since the runner starts from rest)
Final speed = 10 m/s
time interval = 2 sec
average speed = ?
The speed is assumed to change at a constant rate
Average speed = (final speed + initial speed)/2
==> (10 + 0)/2 = 10/2 = 5 m/s
Which scientist demonstrated that light is the visible component of a larger spectrum of electromagnetic waves
While flying due east at 33 m/s, an airplane is also being carried due north at 12 m/s by the wind. What is the plane’s resultant velocity?
Answer:
35.11 m/s
Explanation:
While flying due east at 33 meters/second, an airplane is also being carried due north at 12 meters/second by the wind, then the plane’s resultant velocity would be 35.11 meters/second.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity.
the mathematical expression for velocity is given by
velocity = total displacement /total time
As given in the problem , while flying due east at 33 m/s, an airplane is also being carried due north at 12 m/s by the wind and we have to find the resultant velocity of the plane,
Resultant velocity = √( 33² + 12²)
= 35.11 meters/second
Thus, the plane’s resultant velocity would be 35.11 meters/second
Learn more about Velocity here, refer to the link;
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what is the difference between temperature and heat
Explanation:
Heat is a form of energy that can transfer from hot body to cold body.Temperature is the degree of hotness and coldness of a body.
Heat is measured in joules, but temp. is measured in Kelvin
Answer:
temperature is the degree of hotness and coldness of the body or an object while heat is the energy transferred from hot to a cooler object as a result if differencein temperature ☺
A person who normally weighs 700 N is riding in an elevator that is moving upward but slowing down at a steady rate. If this person is standing on a bathroom scale insidethe elevator, what would the scale read?A) more than 700 NB) less than 700 NC) 700 ND) It could be more or less than 700 N, depending on whether the magnitude of the accelerationis greater than or less than 9.8 m/s2.
Answer:
B) less than 700 N
Explanation:
Given;
normal weight of the person, W = 700 N
An elevator moving upward but slowing down at a steady rate, shows that upward force is less than downward force, thus, the reading on the scale will be less than 700 N.
Also, from Newton's second law
R - mg = ma
where;
R is the reading on the scale
mg is the weight of the person = W = 700 N
a is negative acceleration upward = -a
R - mg = -ma
R = mg - ma
Thus, If this person is standing on a bathroom scale inside the elevator, the scale will read less than 700 N.
B) less than 700 N.
A circular loop of wire 1.0 cm in radius carries a current of 40 A. The magnetic field at the center of the loop is
Answer:
The magnetic field at the center of the loop is 2.51 × 10⁻³ T
Explanation:
The magnetic field at the center of a circular loop is given by
B = μ₀I/2r
Where B is the magnetic field strength in Teslas (T)
μ₀ is the permeability of free space
μ₀ = 4π ×10⁻⁷ N/A²
I is the current in Amperes (A)
and r is the radius of the loop in meters (m)
From the question,
r = 1.0 cm
Convert this to meter (m)
1.0 cm = 1.0 × 10⁻² m = 0.01 m
∴ r = 0.01 m
I = 40 A
Hence, the magnetic field at the center of the loop is
B = μ₀I/2r
B = (4π ×10⁻⁷ × 40) / (2 × 0.01)
B = 5.0265 × 10⁻⁵ / 0.02
B = 2.51 × 10⁻³ T
Hence, the magnetic field at the center of the loop is 2.51 × 10⁻³ T
As you did above for the gas, now estimate the number of molecules found in a cubic centimeter of a liquid at ordinary pressure and temperature.
Answer:
There are [tex]3.372 \times 10^{22}[/tex] molecules in a cubic centimeter of water at ordinary pressure and temperature.
Explanation:
Let suppose that liquid is water at a pressure of a atmosphere and a temperature of 25 ºC. Due to incompresibility of liquids, water density does not have any change of importance due to changes in pressure and temperature.
Density and molar mass of water are 1 gram per cubic centimeter and 18.015 grams per mole. The mass of water in a cubic centimeter ([tex]m[/tex]), measured in grams, is:
[tex]m = \rho\cdot V[/tex]
Where:
[tex]\rho[/tex] - Density, measured in grams per cubic meter.
[tex]V[/tex] - Volume of the sample, measured in cubic meters.
Given that [tex]\rho = 1\,\frac{g}{cm^{3}}[/tex] and [tex]V = 1\,cm^{3}[/tex], the mass of water is:
[tex]m = \left(1\,\frac{g}{cm^{3}} \right)\cdot (1\,cm^{2})[/tex]
[tex]m = 1\,g[/tex]
The amount of moles ([tex]n[/tex]) inside the sample is:
[tex]n = \frac{m}{M}[/tex]
Where:
[tex]m[/tex] - Mass of the sample, measured in grams.
[tex]M[/tex] - Molar mass, measured in grams per mole.
If [tex]m = 1\,g[/tex] and [tex]M = 18.015\,\frac{g}{mole}[/tex], then:
[tex]n = \frac{1\,g}{18.015\,\frac{g}{mole} }[/tex]
[tex]n = 0.056\,mole[/tex]
According to the Avogadro's Principle, there are [tex]6.022\times 10^{23}[/tex] molecules per mole. Hence, the number of molecules in a cubic centimeter of water at ordinary pressure and temperature is determined by simple rule of three:
[tex]x = (0.056\,mole)\times\left(6.022\times 10^{23}\,\frac{molecules}{mole} \right)[/tex]
[tex]x = 3.372\times 10^{22}\,molecules[/tex]
There are [tex]3.372 \times 10^{22}[/tex] molecules in a cubic centimeter of water at ordinary pressure and temperature.
Why is it beneficial to perform focal point of a convex lens exercises in a dimly-lit room?
What is the focal length of a convex lens that produces an image on a screen 40 cm away with an object placed 10 cm from the lens? What is the magnification? Is the image inverted or upright? Show all calculations in your answer.
Explanation:
It is given that,
The object distance from the lens is 10 cm, u = -10 cm
Image is formed at a distance of 40 cm away from the lens, u = 40 cm
The lens formula is : [tex]\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}[/tex], v is image distance
[tex]\dfrac{1}{40}-\dfrac{1}{-10}=\dfrac{1}{f}\\\\f=8\ cm[/tex]
The focal length is 8 cm
Magnification,
[tex]m=\dfrac{v}{u}\\\\m=\dfrac{40}{-10}\\\\m=-4[/tex]
The magnification is negative, it means that the formed image is inverted.
the density of mercury is 13.6 g/ml. what is its density in lbs/L
Answer
density of mercury is 13.6 g/ml and that 1 lb = 0.45 kg.
Calculate the average volume per molecule for an ideal gas at room temperature and atmospheric pressure. Then take the cube root to get an estimate of the average distance between molecules. How does this distance compare to the size of a molecule
Complete Question
Calculate the average volume per molecule for an ideal gas at room temperature and atmospheric pressure. Then take the cube root to get an estimate of the average distance between molecules. How does this distance compare to the size of a molecule like [tex]N_2[/tex]?
Answer:
The average volume per molecule is
[tex]\frac{V}{N} = 4.09 *10^{-26} \ m^3/molecule[/tex]
The average distance between molecules
[tex]d = 3.45 *10^{-9} \ m[/tex]
The size of [tex]N_2[/tex] is 100 times smaller than the obtained value
Explanation:
From the question we can deduce that we are considering an ideal
Generally the ideal gas equation is mathematically represented as
[tex]PV = NkT[/tex]
Here T is the room temperature with value T = 300 \ K
k is the Boltzmann constant with value [tex]k = 1.38 *10^{-23} \ J/K[/tex]
P is the atmospheric pressure with value [tex]P = 1.0 *10^{5} \ N/m^2[/tex]
N is the number of molecules
Now the volume per molecule is mathematically deduced from the above equation as
[tex]\frac{V}{N} = \frac{kT}{P}[/tex]
=> [tex]\frac{V}{N} = \frac{ 1.381 *10^{-23} * 300}{ 1.0*10^{5}}[/tex]
=> [tex]\frac{V}{N} = 4.09 *10^{-26} \ m^3/molecule[/tex]
Now the distance is mathematically evaluated as
[tex]d = \sqrt{\frac{V}{N} }[/tex]
=> [tex]d = \sqrt[3]{4.09*10^{-26}}[/tex]
=> [tex]d = 3.45 *10^{-9} \ m[/tex]
Generally the size of [tex]N_2[/tex] is 115 pm which is 100 times smaller than the obtained value
Generally the size of [tex]H_2O[/tex] is [tex]95.84 \ pm[/tex] which is 10 times smaller than the obtained value
Based on the ideal gas equation, the calculated values are as follows:
the average volume per molecule is 4.09 × 10^-23 m^3/moleculethe average distance between molecules is 3.45 nmthe N2 molecule is about 30 times smaller than the average distance between molecules.How can the average volume per molecule be calculated?The average volume per molecule is calculated using the given formula derived from the ideal gas equation:
V/n = kT/Pwhere:
V = gas volumen = number of molesk is Boltzmann constant = 1.38 × 10^-23 J/KT is temperature, and P is pressureAt room temperature and atmospheric pressure;
T = 300 k
P = 1.0 × 10^5 N/m^2
Substituting the values in the equation above to calculate the average volume per molecule, V/n:
V/n = 1.38 × 10^-23 × 300/1.0 × 10^5 N/m^2
V/n = 4.09 × 10^-23 m^3/molecule
Thus, the average volume per molecule is 4.09 × 10^-23 m^3/molecule
How can the average distance between molecules be determined?The average distance between molecules can be determined by using the formula:
[tex]d = \sqrt[3]{ \frac{v}{n} } [/tex]
Substituting the values for V/n
[tex]d = \sqrt[3]{4.09 \times {10}^{ - 23} } [/tex]
d = 3.45 × 10^-9 m or 3.45 nm
Therefore, the average distance between molecules is 3.45 nm
A molecule of N2 has an average size of 115 pm or 0.115 nm.
Comparing the two values:
3.45/0.115 = 30
Therefore, the N2 molecule is about 30 times smaller than the average distance between molecules.
Learn more about distance between molecules ans Ideal gas equation at: https://brainly.com/question/14375674
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What is operational definition and two examples
Answer:
An example of operational definition of the term weight of an object, operationalized to a degree, would be the following: "weight is the numbers that appear when that object is placed on a weighing scale"
A linear network has a current input 7.5 cos(10t + 30°) A and a voltage output 120 cos(10t + 75°) V. Determine the associated impedance.
Answer:
16∠45° Ω
Explanation:
Applying,
Z = V/I................... Equation 1
Where Z = Impedance, V = Voltage output, I = current input.
Given: V = 120cos(10t+75°), = 120∠75°, I = 7.5cos(10t+30) = 7.5∠30°
Substitute these values into equation 1
Z = 120cos(10t+75°)/7.5cos(10t+30)
Z = 120∠75°/ 7.5∠30°
Z = 16∠(75°-30)
Z = 16∠45° Ω
Hence the impedance of the linear network is 16∠45° Ω
The constant of proportionality between charge and voltage is the:________.
a) Capacitor
b) Capacitance
c) Farad
d) None of the above
Answer:
The constant of proportionality between charge and voltage is the capacitance.
Explanation:
The capacitance ([tex]C[/tex]), measured in farads, is the ratio of charge to voltage, that is:
[tex]C = \frac{Q}{V}[/tex]
Where:
[tex]Q[/tex] - Charge, measured in coulombs.
[tex]V[/tex] - Voltage, measured in volts.
If charge is clear, it is easy to concluded that capacitante is a constant of direct proportionality.
Hence, the correct answer is B.
has current 150 A and a height of 6.0 m above the ground, what magnetic field does the line produce at ground level
Complete question:
Currents in dc transmission lines can be 100 A or higher. Some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. For a line that has current 150 A and a height of 6.0 m above the ground, what magnetic field does the line produce at ground level?
Answer:
The magnetic field the line produces at ground level is 5 x 10⁻⁶ T.
Explanation:
Given;
current in the dc transmission line, I = 150 A
height above ground level, R = 6 m
The transmission line will be treated as current in a long straight wire.
Thus, the magnetic field produced at the ground level is given as magnetic field in a long straight conductor.
[tex]B = \frac{\mu_o I}{2\pi R}[/tex]
where;
μ₀ is permeability of free space = 4π x 10⁻⁷ T.m/A
[tex]B = \frac{4\pi*10^{-7} * 150}{2\pi * 6}\\\\B = 5*10^{-6} \ T[/tex]
Therefore, the magnetic field the line produces at ground level is 5 x 10⁻⁶ T.
what would be the behavior of an object that was immersed in a fluid if the object and the fluid had the same density
Answer:
The object will remain where it was placed on the fluid
Explanation:
If an object is immersed in a fluid, with both the object and the fluid having the same density, the force of buoyancy (the force acting upward) will be equal to the gravitational force (the weight pulling the object down) making the object remain in the position it was placed in the fluid. Meaning it will neither sink down or float through the surface.
For practical purpose, it should however be noted that the chances of this happening is very low.
NOTE: When an object is less dense than the liquid/fluid, it will float and when it is more dense than the liquid, it will sink
he Himalayas now reach an elevation of 8.8 km, and radiometric dating suggests that their uplift began about 45 million years ago. Assuming a constant rate of uplift, how fast did the Himalayas rise?
Answer:
v = 6.20 10⁻¹² m / s, v = 1.96 10⁻² cm/year
Explanation:
This is a kinematics problem, specifically of uniform motion
v = d / t
let's reduce the magnitudes to the SI system
d = 8.8 km (1000 m / 1 km) = 8.8 10³ m
t = 45 10⁶ years (365 day / 1 year) (24 h / 1 day) (3600 s / 1h)
t = 1,419 10¹⁵ s
let's calculate the speed
v = 8.8 10³ / 1.1419 10¹⁵
v = 6.20 10⁻¹² m / s
This is the correct unit of the SI system, but it is more common to give the value in centimeters per year, so let's reduce the value
v = 8.8 105 / 45 106
v = 1.96 10⁻² cm/year
To which layer can geologists apply the principle of faunal succession to determine the age of the layer?
A. Layer C
B. Layer A
C. Layer D
D. Layer B
An oil tanker took 7.2 hours to travel from city A to city B at an
average speed of 60 mph. If a passenger boat took 18 fewer
hours than the oil tanker to complete the same journey, what
was the average speed of the passenger boat?
Answer: 80
Explanation: 7.2 hours x 60mph = 432 m
7.2 hrs - 1.8 hrs= 5.4 hrs
432m/5.4hrs = 80
Answer: 80 mph
Explanation:
Just is
What are the laws of aerodynamics?
Answer:
Lift, weight, thrust and drag.
Answer:
According to Newton's first law of motion (inertia), an object at rest will remain at rest, or an object in motion will continue in motion at the same speed and in the same direction, until an outside force acts on it. For an aircraft to taxi or fly, a force must be applied to it. It would remain at rest without an outside force. Once the aircraft is moving, another force must act on it to bring it to a stop. It would continue in motion without an outside force. This willingness of an object to remain at rest or to continue in motion is referred to as inertia.
Newton's Second Law of Motion
The second law of motion (force) states that if a object moving with uniform speed is acted upon by an external force, the change of motion (acceleration) will be directly proportional to the amount of force and inversely proportional to the mass of the object being moved. The motion will take place in the direction in which the force acts. Simply stated, this means that an object being pushed by 10 pounds of force will travel faster than it would if it were pushed by 5 pounds of force. A heavier object will accelerate more slowly than a lighter object when an equal force is applied.
Newton's Third Law of Motion
The third law of motion (action and reaction) states that for every action (force) there is an equal and opposite reaction (force). This law can be demonstrated with a balloon. If you inflate a balloon with air and release it without securing the neck, as the air is expelled the balloon moves in the opposite direction of the air rushing out of it.