The answer is A. velocity .
Velocity is a vector quantity because it need magnitude as well as direction to be defined.
You want to find out how many atoms of the isotope 65Cu are in a small sample of material. You bombard the sample with neutrons to ensure that on the order of 1% of these copper nuclei absorb a neutron. After activation, you turn off the neutron flux and then use a highly efficient detector to monitor the gamma radiation that comes out of the sample. Assume half of the 66Cu nuclei emit a 1.04-MeV gamma ray in their decay. (The other half of the activated nuclei decay directly to the ground state of 66Ni.) (Enter your answer using one of the following formats: 1.2e-3 for 0.0012 and 1.20e 2 for 120.)
Required:
a. If after 10 min (two half-lives) you have detected 10000 MeV of photon energy at 1.04 MeV, approximately how many 65Cu atoms are in the sample?
b. Assume the sample contains natural copper. Refer to the isotopic abundances listed in your text (Chemical and Nuclear Information for Selected Isotopes) and estimate the total mass of copper in the sample.
Answer:
a) number of copper atoms 65 (⁶⁵Cu) is 7.692 10⁶ atoms
b) m_total Cu = 1.585 10⁹ u = 2.632 10⁻¹⁸ kg
Explanation:
a) For this exercise let's start by using the radioactive decay ratio
N = N₀ [tex]e^{- \lambda t}[/tex]o e - lambda t
The half-life time is defined as the time it takes for half of the radioactive (activated) atoms to decay, therefore after two half-lives there are
N = ½ (½ N₀) = ¼ N₀
N₀ = 4 N
in each decay a photon is emitted so we can use a direct rule of proportions. If an atom emits a photon it has Eo = 1,04 Mev, how many photons it has energy E = 10,000 MeV
# _atoms = 1 atom (photon) (E / Eo)
# _atoms = 1 10000 / 1.04
# _atoms = 9615,4 atoms
N₀ = 4 #_atoms
N₀ = 4 9615,4
N₀= 38461.6 atoms
in the exercise indicates that half of the atoms decay in this way and the other half decays directly to the base state of Zinc, so the total number of activated atoms
N_activated = 2 # _atoms
N_activated = 2 38461.6
N_activated = 76923.2
also indicates that 1% = 0.01 of the nuclei is activated by neutron bombardment
N_activated = 0.01 N_total
N_total = N_activated / 0.01
N_total = 76923.2 / 100
N_total = 7.692 10⁶ atoms
so the number of copper atoms 65 (⁶⁵Cu) is 7.692 10⁶
b) the natural abundance of copper is
⁶³Cu 69.17%
⁶⁵Cu 30.83%
Let's use a direct proportion rule. If there are 7.692 10⁶ ⁶⁵Cu that represents 30.83, how much ⁶³Cu is there that represents 69.17%
# _63Cu = 69.17% (7.692 10⁶ / 30.83%)
# _63Cu = 17.258 10⁶ atom ⁶³Cu
the total amount of comatose is
#_total Cu = #_ 65Cu + # _63Cu
#_total Cu = (7.692 + 17.258) 10⁶
#_total Cu = 24.95 10⁶
the atomic mass of copper is m_Cu = 63.546 u
m_total = #_totalCu m_Cu
m_total = 24.95 10⁶ 63,546 u
m_total = 1.585 10⁹ u
let's reduce to kg
m_total Cu = 1.585 10⁹ u (1,66054 10⁻²⁷ kg / 1 u)
m_total Cu = 2.632 10⁻¹⁸ kg
The model shows the star Wolf 359, the sun, and Star X. It takes 7.8 years for light produced on Wolf 359 to reach the sun.
If Star X is 50 times as far from the sun as Wolf 359 is, how far is Star X from the sun, to the nearest light-year?
Answer:
390 light-years
Explanation:
50 x 7.8 =390
A geologist notices that a river is eroding its valley at a constant rate. Knowing the height of the valley walls, how could the geologist figure out when the river started carving the valley?
A.
Count growth rings of trees growing on the valley floor.
B.
Divide the height of the valley walls by the rate of erosion.
C.
Fill up the river valley with rocks, and time how long it takes the rocks to wash out.
D.
Sit and observe the river for a few hours until the valley walls double in height.
Answer:
B.
Divide the height of the valley walls by the rate of erosion.
Explanation:
There is a relationship between the rate of erosion and the hieght at which it is eroded according to Newton's law of motion. In the case of the scenario above, the best way to determine the time the river started carving the valley would be the division of the height of the valley walls by the rate of erosion.
1. Describe the following energy transformations for the following scenario:
A student plays piano in music class.
Answer:
Explanation:
iphotosynthesis 2coal burning 3electric motor 4 electricity generator 5 waterturbines 6 solar bulb
Which statement best describes work in the scientific sense?
O A. Work is the sum of the distances an object moves due to the
forces applied to it.
O B. Work is the number of tasks done in the amount of time needed to
complete them.
O C. Work is the ratio of the force acting on an object and the distance
the object travels.
O D. Work is the product of a force and the distance an object moves
because of the force.
Answer:
the answer is D I tought
Do anyone answer this question
Answer:
B) 10^-2 cm/s
in term of meter. it is 10^-4 m/s
Explanation:
A 2:2 kg toy train is con ned to roll along a straight, frictionless track parallel to the x-axis. The train starts at the origin moving at a speed of 1:6m=s in the +x direction, and continues until it reaches a position 7:5m down the track from where it started. During its journey, it experiences a force pointing in the same direction as the vector 0:6 +0:8 , with magnitude initially 2:8N and decreasing linearly with its x-position to 0N when the train has finished its journey.
Required:
a. Calculate the work done by this force over the entire journey of the train.
b. Find the speed of the train at the end of its journey.
Answer:
a) 10.51 J
b) 3.48 m/s
Explanation:
Given data :
mass of train ( M ) = 2.2 kg
Given initial velocity ( u ) = 1.6 m/s
a) calculating work done by the force over the journey of the train
F = mx + b ------ ( 1 )
m = slope = ( Δ f / Δ x ) = 2.8 / -7.5 = - 0.373 N/m
x = distance travelled on the x axis by the train = 7.5 m
F = force experienced by the train = 2.8 N
x = 0
∴ b = 2.8
hence equation 1 can be written as
F = ( -0.373) x + 2.8 ----- ( 2 )
hence to determine the work done by the force
W = [tex]\int\limits^7_0 { ( -0.373) x + 2.8 )} \, dx[/tex] Note: the limits are actually 7.5 and 0
∴ W ( work done ) = -10.49 + 21 = 10.51 J
b) calculate the speed of the train at the end of its journey
we will apply the work energy theorem
W = 1/2 m*v^2 - 1/2 m*u^2
∴ V^2 = 2 / M ( W + 1/2 M*u^2 ) ( input values into equation )
V^2 = 12.11
hence V = 3.48 m/s
stored energy is _________ ___________
kinetic energy
energy in motion
potential energy
Answer:
Potential energy
Explanation:
Potential energy is stored energy
Student 1 and student 2 talk about the speed of the truck
Answer:
Explanation:
any more explanation?
A rock falls from a cliff and hits the ground at a velocity of 31m/s. How long did it take to fall?
Answer:
i dont know man
Explanation:
i dont know man
ILL GIVE BRAINLIST PLS In which circuit does charge reverse direction many times per second?
A. A DC circuit
B. A combined circuit
C. A parallel circuit D. An AC circuit
Answer: D. An AC circuit
Explanation:
I took it on a test and it was correct ; )
A thin uniform rod (length = 1.2 m, mass = 2.0 kg) is pivoted about a horizontal, frictionless pin through one end of the rod. (The moment of inertia of the rod about this axis is ML2/3.) The rod is released when it makes an angle of 37° with the horizontal. What is the angular acceleration of the rod at the instant it is released (in rad/s^2)?
Answer:
A: 9.8 rad/s2
B: 7.4 rad/s2
C: 8.4 rad/s2
D: 5.9 rad/s2
E: 6.5 rad/s2
I think the answer is A 9.8rad/s2
has a man he has married many women but has never been married before who is he
Answer:
Explanation:
The answer is a priest or a moulana
A fisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. It takes a time of 2.00 s for the boat to travel from its highest point to its lowest, a total distance of 0.600 m . The fisherman sees that the wave crests are spaced a horizontal distance of 6.40 m apart.
Required:
a. How fast are the waves traveling?
b. What is the amplitude of each wave?
c. If the total vertical distance traveled by the boat were 0.30 m but the other data remained the same, how would the answers to parts (a) and (b) be affected?
Answer:
a. Speed = 1.6 m/s
b. Amplitude = 0.3 m
c. Speed = 1.6 m/s
Amplitude = 0.15 m
Explanation:
a.
The frequency of the wave must be equal to the reciprocal of the time taken by the boat to move from the highest point to the highest point again. This time will be twice the value of the time taken to travel from the highest point to the lowest point:
frequency = [tex]\frac{1}{2(2\ s)}[/tex] = 0.25 Hz
The wavelength of the wave is the distance between consecutive crests of wave. Therefore,
Wavelength = 6.4 m
Now, the speed of the wave is given as:
Speed = (Frequency)(Wavelength)
Speed = (0.25 Hz)(6.4 m)
Speed = 1.6 m/s
b.
Amplitude is the distance between the mean position of the wave and the extreme position. Hence, it will be half the distance between the highest and lowest point:
Amplitude = (0.5)(0.6 m)
Amplitude = 0.3 m
c.
frequency = [tex]\frac{1}{2(2\ s)}[/tex] = 0.25 Hz
Speed = (Frequency)(Wavelength)
Speed = (0.25 Hz)(6.4 m)
Speed = 1.6 m/s
Amplitude = (0.5)(0.3 m)
Amplitude = 0.15 m
Scientists are constantly exploring the universe, looking for new planets that support life similar to the life on
Earth. A new planet that supports life would have all of the following characteristics except -
A. a gaseous atmosphere.
B. an orbiting moon.
C. liquid water.
D. protection from radiation.
A new planet that supports life would have all the following characteristics except an orbiting moon. Hence, option B is correct.
What is a Planet?An enormous, spherical celestial object known as a planet is neither a star nor its remains. The nebular hypothesis, which states how an interstellar cloud falls out of a nebula to produce a young protostar encircled by a protoplanetary disk, is now the best explanation for planet formation.
By gradually accumulating material under the influence of gravity, or accretion, planets develop in this disk.
The rocky planets Mercury, Venus, Earth, and Mars, as well as the giant planets Jupiter, Saturn, Uranus, and Neptune, make up the Solar System's minimum number of eight planets. These planets all revolve around axes that are inclined relative to their respective polar axes.
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Which macronutrient is made up of carbon and hydrogen elements joined together in long groups called hydrocarbons?
Proteins Magnesium Potassium Fats
Answer:
FATS
Explanation:
Fats are made up of carbon and hydrogen elements joined together in long groups called hydrocarbons. The simplest unit of fat is the fatty acid, of which there are two types: saturated and unsaturated.
The macronutrient which is made up of carbon and hydrogen elements joined together in long groups called hydrocarbons is: D. Fats.
A macronutrient refers to a very large molecule (structure) that comprises covalently bonded organic atoms (hydrocarbons) and smaller molecular structures (monomers).
In Science, macronutrients are grouped into four (4) main categories and these are;
Nucleic acid.Carbohydrates.Proteins.Fats (Lipids).Fats (Lipids) are macronutrients that are typically made up of both carbon and hydrogen elements, which are joined together in long groups referred to as hydrocarbons.
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I am b o r e d, I am very very b o r e d!
I'm b o r e d with Lazarbeam Quarantine edition
episode 2352 because apparently the quarantining never ends :(
Lucy moves down the hall at 3.5 m/s. When he sees Luke coming, he slows down. After 4.0 s, he is moving at 2.1. m/s. What is his acceleration?
Answer:
Acceleration, a = 0.35 m/s²
Explanation:
Given the following data;
Initial velocity, u = 3.5 m/s²
Final velocity, v = 2.1 m/s²
Time, t = 4 secs
To find the acceleration, we would use the first equation of motion;
V = u - at (the sign is negative because Lucy is slowing down).
Substituting into the formula, we have;
2.1 = 3.5 - a(4)
2.1 = 3.5 - 4a
4a = 3.5 - 2.1
4a = 1.4
a = 1.4/4
a = 0.35 m/s²
What is a negative effect of increased carbon dioxide within the carbon cycle?
Answer:
Carbon dioxide controls the amount of water vapor in the atmosphere and thus the size of the greenhouse effect. Rising carbon dioxide concentrations are already causing the planet to heat up
Explanation:
Hope it helps! Correct me if I am wrong
Im sure about my answer
A sound wave travels with a velocity of 1.5 m/s and has a frequency of 500 Hz. What is its wavelength?
Two point charges, initially 3 cm apart, are moved to a distance of 1 cm apart. By what factor does the resulting electric force between them change?
A. 3
B. 1/9
C. 1/3
D. 9
A circular cylinder has a diameter of 3.0 cm and a mass of 25 g. It floats in water with its long axis perpendicular to the water's surface. It is pushed down into the water by a small distance and released; it then bobs up and down. Part A What is the oscillation frequency
Answer:
f = 5.3 Hz
Explanation:
To solve this problem, let's find the equation that describes the process, using Newton's second law
∑ F = ma
where the acceleration is
a = [tex]\frac{d^2 y}{dt^2 }[/tex]
B- W = m \frac{d^2 y}{dt^2 }
To solve this problem we create a change in the reference system, we place the zero at the equilibrium point
B = W
In this frame of reference, the variable y' when it is oscillating is positive and negative, therefore Newton's equation remains
B’= m [tex]\frac{d^2 y'}{dt^2 }[/tex]
the thrust is given by the Archimedes relation
B = ρ_liquid g V_liquid
the volume is
V = π r² y'
we substitute
- ρ_liquid g π r² y’ = m \frac{d^2 y'}{dt^2 }
[tex]\frac{d^2 y'}{dt^2} + \rho_liquid \ g \ \pi r^2/m ) y' \ =0[/tex]
this differential equation has a solution of type
y = A cos (wt + Ф)
where
w² = ρ_liquid g π r² /m
angular velocity and frequency are related
w = 2π f
we substitute
4π² f² = ρ_liquid g π r² / m
f = [tex]\frac{1}{2\pi } \ \sqrt{ \frac{ \rho_{liquid} \ \pi r^2 \ g}{m } }[/tex]
calculate
f = [tex]\frac{1}{2 \pi } \sqrt{ \frac{ 1000 \ \pi \ 0.03^2 \ 9.8 }{0.025} }[/tex]
f = 5.3 Hz
Find the speed of a wave with a frequency of 18 Hz and a wavelength of 6 meters. Show work. WILL MARK BRAINLIEST IF CORRECT
Answer:
so i would say 11.4 i dont have work only this link
Explanation:
https://flexbooks.ck12.org/cbook/ck-12-physics-flexbook-2.0/section/11.4/primary/lesson/wave-speed-ms-ps
Imagine you are on a space mission and you are 6 AU's from the Sun and you use a light sensor to measure the brightness of the Sun. The amount of sunlight received per square centimeter would be different by what factor compared to the same measurement on Earth at AU
Answer:
36 times less.
Explanation:
The distance from you to the sun is 6AU's, and from the sun to the earth is 1 AU.
Therefore,
At Earth sunlight received per unit cm² is:
[tex]I_{earth} = \dfrac{I_o}{4 \pi \times (1)^2}[/tex]
[tex]I_{earth} = \dfrac{I_o}{4 \pi}[/tex]
[tex]I_{me} =\dfrac{I}{4 \pi (6)^2}[/tex]
[tex]I_{me} = \dfrac{I_o}{36(4 \pi)}[/tex]
Thus, [tex]I_{earth} = 36 \times I_{me}[/tex]
Thus, the right answer is 36 times less.
Student Exploration: Energy Conversion in a SystemNCVPS Chemistry Fall 2014Vocabulary: energy, gravitational potential energy, heat energy, kinetic energy, law of conservation of energy, specific heat capacityPrior Knowledge Questions (Do these BEFORE using the Gizmo.)A battery contains stored energy in the form of chemical energy.1. What are some examples of devices that are powered by batteries? ____________________________________________________________________________________________2. What different forms of energy are dmonstrated by these devices? ___________________ _________________________________________________________________________Gizmo Warm-upEnergy constantly changes from one form to another, but in a closed system, the total amount of energy always remains the same. This concept is known formally as the law of conservation of energy.The Energy Conversion in a System Gizmo™ allows you to observe the law of conservation of energy in action. In the Gizmo, a suspended cylinder has gravitational potential energy. When the cylinder is released, the
Answer:
a) Battery-operated devices have: small led lights, flashlights, wireless keyboards and mice, watches, electronic weights
b) ed lights and flashlights transform into light energy and thermal energy
c) Em₀ = U = m gh, Em_f = K = ½ m v²
Explanation:
In this exercise ask to complete the sentences
a) Battery-operated devices have: small led lights, flashlights, wireless keyboards and mice, watches, electronic weights
b) These devices transform the chemical energy stored in the batteries into other forms of energy.
Led lights and flashlights transform into light energy and thermal energy
Keyboards transform into electromagnetic energy that is emitted
clocks transform to mechanical energy from the movement of the needles
Electronic weights transforms the chemical energy of the baria into gravitational potential energy that prevents the movement of the plate and this translates into the reading of the body weight
c) The total energy of the cylinder mechanical energy when sustained is
Em₀ = U = m gh
it is transformed as it descends into kinetic energy, at any point
Emₙ = K + U = 1/2 m v² + m g y
at the lowest point of the trajectory all energy is transformed
Em_f = K = ½ m v²
Some thermometers contain alcohol. Alcohol is used in thermometers because
A. is soluble in water
B. is a clear gas when it evaporates
C. expands and contracts easily
D. has a high density
Answer:
Explanation:
Option C is the correct answer
Some thermometers contain alcohol. Alcohol is used in thermometers because expands and contracts easily. The correct option is C.
What is thermometer?Thermometer is the temperature measuring device which consists of a liquid in the bulb which expands as the temperature is increased.
The liquid metal used in the thermometer must have the property to respond on the hotness and coldness rapidly.
In place of mercury, some thermometers use alcohol because an alcohol has a very low freezing point as compared to the Mercury.
Thus, the correct option is C.
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Some thermometers contain alcohol. Alcohol is used in thermometers because expands and contracts easily.
Which two options describe physical properties of matter
Q10. Refer to the Condon table to answer question
Second letter
UUU
UCU
UGU
OUC
UCO
UAC
Leu
UAA Btop UOA Stop
UCG UAG Stop UGOT
CU
CCU
CAU CGU
CUC
ССС
САС
Leu
CUA
CGC
Pro
CCA
CAA COA
CUG
CCG
AD
RoecoDoo Do
Asn
AUU
ACU
AUC File
ACC
AUA АСА
AUG Met ACO
AAU
ААС
ΑΛΛΑ
LANG
AGU
Ser
AGC
Thr
Jue AGA
Jara
AGG
sp
GU
QUC
GUA
GUG
GCU GAU
GCC
Ala
GAC
GCA GAA
OCG GAG
GOC
GGA
Jolu 900
Write the mRNA copy of this DNA CCG GA
GCT (original) | Imk]
Use the Condon table above to list all the amin
Answer:
so you have a question
Explanation:
either way, have a nice day
NASA’s Tracking and Data Relay Satellite (TDRS) System constellation resides at geosynchronous orbit (35,000km) altitude. If a technician at the Goddard Spaceflight Center in Maryland initiates a transmission to the Johnson Spaceflight Center in Houston over TDRS, how long will it be until JSC detects the transmission (one-way latency)? You may assume there is negligible processing delay on the satellite, and that c = 3x108 m/sec.
Answer:
35,000 km = 35,000,000 m = 3.5 E107 m
t = S / v = 3.5 * 10E7 / 3.0 E10E8 = .117 sec
describe briefly how you can a body
Answer:
what
you need to elaborate
Answer: Can you please write question clearly.
Explanation: