Answer:
Explanation:
Bigger pushes and pulls cause bigger changes in an object's motion or shape. When objects collide, contact forces transfer energy so as to change the objects' motions. When two objects interact, each one exerts a force on the other, and these forces can transfer energy between them.
A freshly prepared sample of radioactive isotope has an activity of 10 mCi. After 4 hours, its activity is 8 mCi. Find: (a) the decay constant and half-life T1/2; (b) How many atoms of the isotope were contained in the freshly prepared sample? (c) What is the sample's activity 30 hours after it is prepared?
Answer:
(a). The decay constant is [tex]1.55\times10^{-5}\ s^{-1}[/tex]
The half life is 11.3 hr.
(b). The value of N₀ is [tex]2.38\times10^{11}\ nuclei[/tex]
(c). The sample's activity is 1.87 mCi.
Explanation:
Given that,
Activity [tex]R_{0}=10\ mCi[/tex]
Time [tex]t_{1}=4\ hours[/tex]
Activity R= 8 mCi
(a). We need to calculate the decay constant
Using formula of activity
[tex]R=R_{0}e^{-\lambda t}[/tex]
[tex]\lambda=\dfrac{1}{t}ln(\dfrac{R_{0}}{R})[/tex]
Put the value into the formula
[tex]\lambda=\dfrac{1}{4\times3600}ln(\dfrac{10}{8})[/tex]
[tex]\lambda=0.0000154\ s^{-1}[/tex]
[tex]\lambda=1.55\times10^{-5}\ s^{-1}[/tex]
We need to calculate the half life
Using formula of half life
[tex]T_{\dfrac{1}{2}}=\dfrac{ln(2)}{\lambda}[/tex]
Put the value into the formula
[tex]T_{\dfrac{1}{2}}=\dfrac{ln(2)}{1.55\times10^{-5}}[/tex]
[tex]T_{\dfrac{1}{2}}=44.719\times10^{3}\ s[/tex]
[tex]T_{\dfrac{1}{2}}=11.3\ hr[/tex]
(b). We need to calculate the value of N₀
Using formula of [tex]N_{0}[/tex]
[tex]N_{0}=\dfrac{3.70\times10^{6}}{\lambda}[/tex]
Put the value into the formula
[tex]N_{0}=\dfrac{3.70\times10^{6}}{1.55\times10^{-5}}[/tex]
[tex]N_{0}=2.38\times10^{11}\ nuclei[/tex]
(c). We need to calculate the sample's activity
Using formula of activity
[tex]R=R_{0}e^{-\lambda\times t}[/tex]
Put the value intyo the formula
[tex]R=10e^{-(1.55\times10^{-5}\times30\times3600)}[/tex]
[tex]R=1.87\ mCi[/tex]
Hence, (a). The decay constant is [tex]1.55\times10^{-5}\ s^{-1}[/tex]
The half life is 11.3 hr.
(b). The value of N₀ is [tex]2.38\times10^{11}\ nuclei[/tex]
(c). The sample's activity is 1.87 mCi.
What must be true for a hypothesis to become generally accepted by
scientists?
A. It must involve lots of complicated math.
B. It must have been tested by many scientists.
O O O O
C. It must be presented by a famous scientist.
D. It must be proven true by one experiment.
Answer:
B It must have been tested by many scientists.
Explanation:
trust me :)
For a hypothesis to become generally accepted by scientists, It must have been tested by many scientists. Hence option B is correct.
What is hypothesis ?A hypothesis is a theory put up to explain a phenomena. A hypothesis must be testable according to the scientific method for it to be considered a scientific hypothesis. Scientific hypotheses are often based on prior findings that cannot be adequately explained by the current body of knowledge. Despite the fact that the terms "hypothesis" and "theory" are sometimes used interchangeably, they are not the same thing. A working hypothesis is an acknowledged theory that has been tentatively supported and is put up for further investigation.
In formal logic, the term "hypothesis" is used to refer to the antecedent of a statement, or in the proposition, in a different sense.
Hence option B is correct.
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What does gravity do to objects as they:
a) are thrown up:
b) fall toward earth:
Answer:
B
Explanation:
Gravity is when objects are pulled down to earth
witch of the following questoons would you expect to see on an interest inventory
Answer: Do you like science experiments ? 1)
Would You enjoy reading a fashion magazine? 2)
Explanation:
Why does sound travel slower at a cold temperature?
Sound moves faster in warmer air than colder air the way bends away from the warm air and back towards of air.
Answer:
Sound travels slower in cold temperatures than in hot temperatures because the particles in cold air are more closely compacted together and move slower compared to the particles of hot air. Thus the sound, vibrations of particles in the atmosphere, will travel slower.
When the white ball strikes the other colored balls, what can you say about the total momentum of all of the balls combined?
Momentum is never created or destroyed. It is conserved.
The cue stick gave the cue ball all the momentum there is on the table. There's nothing on the table that can pour in any more momentum.
After the strike, with 15 or 16 balls rolling every which way around the table, the total momentum of all of them combined will be the same as the cue ball's momentum right now, before the strike.
which other team sport basketball is the most like.
hi
Answer: mmm... If you mean most like Basketball it's net ball but i don't know much about Basket ball teams
Explanation:
You walk east for 30 m, then decide to walk north foranother 30 m. What is the angle of direction of your displacement?
Answer:
Displacement is 42.426 m NE and the angle is opposite/adjacent or 30/30 which would equal 1 degree which doesn't seem right but hopefully its an answer.
Explanation:
Doe the baby diaper tabs go to the front or back. Huggies diaper.
Answer:
back lol
Explanation:
Pull the tabs and wrap around to stick to the front of the diaper:)
Answer:
Front of the diaper
You take the straps that are connected to the back of the diaper and pull the. forward to attach to the front.
hope this helps.
5)
(64(6-2) =
A)
62
B)
8-9
C)
122
12-8
Answer:
B 8-9 because you had to subtract that number or simplify. then your answer is 8-9
what are three effects of using only non-renewable resources? please help
list 3 lessons we learned from history to handle pandemic
Answer:
1- impact
2. Inequalities
4. Controllability
Explanation:
Most _________ rely on sellers offering their goods or services in exchange for money from buyers
Answer:
Businesses
Explanation:
I think not sure tho
The air in a scuba tank is under more than 200 times the normal air pressure. Why should a filled scuba tank never be left in a hot car for an extended period of time?
Answer:
Burst open
Explanation:
it could create an explosion cause after some time the air wont be good anymore and staying inside a hot car is like someone sitting an oven it would burst open and create an explosion depending on the size of it
difference between gravity and gravitation
Answer:
Gravitation is the attractive force existing between any two objects that have mass. The force of gravitation pulls objects together. Gravity is the gravitational force that occurs between the earth and other bodies. Gravity is the force acting to pull objects toward the earth.
Find the 7th term of the geometric sequence
1/8, 1/2, 2, ...
Answer:
512
Explanation:
Given sequence:
1/8, 1/2, 2, ...
Unknown:
The 7th term of the geometric sequence = ?
Solution:
To solve this problem, we apply the formula below;
Sₙ = arⁿ⁻¹
a is the first term
r is the common ratio
n is the nth term
r = [tex]\frac{\frac{1}{2} }{\frac{1}{8} }[/tex] = [tex]\frac{1}{2} x 8[/tex] = 4
Input the parameters and solve;
Sₙ = [tex]\frac{1}{8}[/tex] x 4⁷⁻¹
Sₙ = [tex]\frac{1}{8}[/tex] x 4⁶ = 512
What is the design process (Engineering Design Process) 5 sentences
What are the SI units for distance and time?
Answer:
distance is meters, time is seconds
Answer:
distance is meters(m)
time is seconds (s)
Explanation:
Give reasons.
a. A stretched catapult has potential energy.
b A stone on ground has zero energy.
C. Rolling a drum is work against friction.
d. Lifting a stone is work against gravity.
e. Work and energy both have same unit.
Cacao beans arrive in a factory from the areas where they grew. At the factory, the best beans are sorted and put into bags. After quality-control workers check the bags, a large truck transports the cacao beans to a commercial chocolate-producing company. Which organelle plays a similar role inside a cell?
A. cytoplasm
B. Golgi body
C. mitochondrion
D. ribosome
E. vacuole
Answer:
B. Golgi body
Explanation:
The Golgi body is the region where proteins are modified, packaged, and transported to the appropriate location, usually outside of the cell.
The cytoplasm is the intracellular fluid/space, the mitochondrion produces energy, the ribosome produces proteins, and the vacuole is a storage organelle.
The Answer is B , Because the golgi body stores stuff for later use.
hope this helps
The gradual change in a species over time is called
a.
mutation.
b.
evolution.
c.
migration.
d.
variation.
PLZ HURRY WILL GIVE BRAINLIEST
Answer: B. Evolution
Explanation:
As species grow older over time they will gradually evolve through natural selection and evolution.
The gradual change in a species over time is known as evolution (b).
The process of evolution occurs through several mechanisms, including mutation, migration, and natural selection.
Mutation (a) is the spontaneous change in the genetic material of an organism. These changes can result in new traits that may be advantageous, disadvantageous, or neutral for survival. When mutations occur, they can introduce genetic variation within a population, which serves as the raw material for evolution.
Natural selection is a crucial factor driving evolution. Individuals with advantageous traits that better suit their environment are more likely to survive and reproduce, passing on these advantageous traits to their offspring. Over generations, the frequency of beneficial traits increases in the population, leading to the adaptation and evolution of the species.
Variation (d) encompasses the differences in physical traits and genetic makeup among individuals within a population. This variation is essential for evolution to occur since it provides the raw material for natural selection to act upon.
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What theory explains the main cause of mountain building, earthquakes, and volcanic eruptions on Earth?
Group of answer choices
the scientific theory of Earth's shift
the scientific theory of magnetism
the scientific theory of Earth's layers
the scientific theory of plate tectonics
Answer:the scientific theory of plate tectonics I believe
Explanation:
A rocket is fired vertically upwards with initial velocity 92 m/s at the ground level. Its engines then fire and it is accelerated at 4m/s2 until it reaches an altitude of 1200 m. At that point the engines fail and the rocket goes into free-fall. Disregard air resistance.
Answer:
The rocket above the ground is in 44 sec.
Explanation:
Given that,
Initial velocity = 92 m/s
Acceleration = 4 m/s²
Altitude = 1200 m
Suppose, How long was the rocket above the ground?
We need to calculate the time
Using equation of motion
[tex]s=ut-\dfrac{1}{2}at^2[/tex]
Put the value into the formula
[tex]1200=92t+\dfrac{1}{2}\times4t^2[/tex]
[tex]2t^2+92-1200=0[/tex]
[tex]t=10\ sec[/tex]
We need to calculate the velocity
Using equation of motion
[tex]v=u+at[/tex]
Put the value into the formula
[tex]v=92+4\times10[/tex]
[tex]v=132\ m/s[/tex]
When the rocket hits the ground,
Then, h'=0
We need to calculate the time
Using equation of motion
[tex]h'=h+ut-\dfrac{1}{2}at^2[/tex]
Put the value into the formula
[tex]0=1200+132t-\dfrac{1}{2}\times9.8t^2[/tex]
[tex]4.9t^2-132t-1200=0[/tex]
[tex]t=34\ sec[/tex]
When the rocket is in the air it is the sum of the time when it reaches 1000 m and the time when it hits the ground
So, the total time will be
[tex]t'=34+10[/tex]
[tex]t'=44\ sec[/tex]
Hence, The rocket above the ground is in 44 sec.
state the various use of a periscope
Answer:
the periscope is an instrument for observation over, around or through the object, obstacle or condition that prevents direct line-of-sight observation from the observer's current position.
Explanation:
the periscope is used to monitor the dangerous chemical reactions in the laboratory and they are used in observing the nuclear.
Answer:
A periscope is used to see objects over the heads of a crowd.It is used by soldiers sitting in a bunker to observe and view the opponents' activities over the ground.It is used by a navy officer sitting in a submarine to see ships over the surface of the water in the sea.It is also useful in submarines to determine the distance of the torpedo and decide the right time for an attack.Classify each of the following chemical reactions. Upper S plus upper O Subscript 2 right arrow upper S upper O subscript 2. Upper C a upper C l subscript 2 plus 2 upper A g upper N upper O subscript 3 right arrow upper C a (upper n upper O subscript 3) subscript 2 plus 2 upper A g upper C l. Upper Z n plus upper C u upper S upper O subscript 4 right arrow upper C u plus upper Z n upper S upper O subscript 4. 2 upper N a subscript 2 upper O right arrow 4 upper N a plus upper O subscript 2.
Answer:
synthesis and combustion
double replacement
single replacement
decomposition only
in that exact order edge 2020
The presented reactions are:
S + O₂ ⇒ SO₂ Synthesis or combination
CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl Double displacement
Zn + CuSO₄ = Cu + ZnSO₄ Single displacement
2 Na₂O = 4 Na + O₂ Decomposition
Let's consider and classify the following reactions.
S + O₂ ⇒ SO₂
This is a synthesis or combination reaction. 2 compounds combine to form another.
CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl
This is a double displacement reaction. Both compounds exchange their cations and anions.
Zn + CuSO₄ = Cu + ZnSO₄
This is a single displacement reaction. A metal displaces other metal from its salt.
2 Na₂O = 4 Na + O₂
This is a decomposition reaction. A compound decomposes into 2 other compounds.
The presented reactions are:
S + O₂ ⇒ SO₂ Synthesis or combination
CaCl₂ + AgNO₃ = Ca(NO₃)₂ + 2 AgCl Double displacement
Zn + CuSO₄ = Cu + ZnSO₄ Single displacement
2 Na₂O = 4 Na + O₂ Decomposition
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explain the relationship between physics and biology
Answer:
Biology is the study of living organisms. Physics is the study of matter and the laws of nature to understand the behavior of matter and the universe.
A chestnut-colored horse mates with a white-colored horse to produce a roan-colored offspring. What type of inheritance pattern does this genetic expression represent? A. Artificial selection B. Codominance C. Incomplete dominance D. Multiple alleles E. Polygenic inheritance
Answer:
The correct option is B.
Codorminance.
Explanation:
The type of inheritance pattern is codorminance because in codorminance the two alleles in the gene are expressed, no allele was able to masked the express on the other allele. The chestnut colored horse allele is expressed likewise the white
colored allele too is expressed none of the two alleles mask the Expression of the other, the two are expressed to give offsprings roan colored which is an indication of the two expression.
Answer:
Codominance
Explanation:
Which is the best estimate for the width of a typical adult hand?
Answer:
About 4-5in
Explanation:
Describe a circumstance where you want friction to work against Newton’s First Law.
Answer:
If I was riding my bicycle, and there was no friction to work against Newton's First Law, I'd give a first push, and I would never be able to turn or stop.
Explanation:
Giving brainlist so plz help
What were John Locke's 3 big ideas
A. Natural rights, consent of the people, and moral obligation to rebel.
OR
B. Life, Liberty, and property
Answer:
Among these fundamental natural rights, Locke said, are "life, liberty, and property." Locke believed that the most basic human law of nature is the preservation of mankind. To serve that purpose, he reasoned, individuals have both a right and a duty to preserve their own lives.
Explanation:
From Google
Can I have brainliest