A sample of cobalt-60 has an activity of 2000 Bq. What will the activity be after 10 years? Cobalt-60 has a half life of 5 years.
Answer:
500.3 Bq
Explanation:
From the formula;
0.693/t1/2 = 2.303/t log (Ao/A)
Where;
t1/12 = half life = 5 years
Ao = initial activity = 2000 Bq
0.693/5 = 2.303/10 log (2000/A)
0.1386= 0.2303 log (2000/A)
0.1386/0.2303 = log (2000/A)
0.6018 = log (2000/A)
(2000/A) = Antilog (0.6018)
(2000/A) = 3.9976
A = 2000/3.9976
A = 500.3 Bq
Which part of this chemical process requires energy? KOH + HBr - KBr + H20 A. Forming bonds in KOH and HBr B. Breaking bonds in KBr and H2O C. Breaking bonds in KOH and HBr D. Forming bonds in KBr and H2O
The chemical process which requires energy is breaking bond in KOH and HBr. Hence, option C is correct.
What is energy?The capacity to perform work is known as energy in physics. Potential, kinematic, thermodynamic, electromagnetic, chemical, nuclear, and other types are all possible.
As energy is transferred through one body to another, there is also heat and work. As a result, heat transfer may result in thermal energy, whereas labor done may result in mechanical power.
As per the given reaction in the question,
KOH + HBr - KBr + H20
Here, in this reaction the chemical process which requires the energy is at the time of breaking of bonds in KOH and HBr at that time the energy is required.
Therefore, it is concluded that breaking bonds in KOH and HBr i.e., option C is correct.
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Which of the following is NOT true about the relationship between electricity and magnetism?
A O All magnets are surrounded by an electric field.
B.
Generators use magnets to induce an electric current.
Motors use electric currents to generate an electric field.
D. A magnetic field can be used to generate an electric current.
Can you please explain and be able to help with further more questions?!
A worker does 196 J of work to lift a bag 2m. What is the mass of the bag?
Work = 196 J = 196 kg.m^2.s^-2
[We know that 1J = 1 kg.m^2.s^-2]
Displacement = 2m
Acceleration (g) = 9.8ms^-2
We know that,
W=Fs and F=ma
So, W = (ma)s
=> W = m×a×s
=> 196 kg.m^2.s^-2 = m×9.8ms^-2×2m
=> 196 kg.m^2.s^-2 = m×19.6m^2.s^-2
=> 196 kg.m^2.s^-2 = m×19.6m^2.s^-2
=> (196 kg.m^2.s^-2)/(19.6m^2.s^-2) = m
=> 10kg = m
So, mass = 10kg
Based on their locations on the periodic table, which two elements would you
expect to form positive ions with a +3 charge?
O A. Nitrogen, N
O B. Aluminum, Al
O C. Phosphorus, P
D. Boron, B
Answer:
i think it would be B. Aluminum, Al and D. Boron, B
Explanation:
since they're both in group 13 and they forms a 3+ ion
PLEASE HELP!!! (15 points)
The only group of elements that DO NOT form ions and are found as monatomic atoms in nature are the:
halogens
noble gases
alkali metals
alkaline earth metals
Answer:
noble gases is those group of elements that DO NOT form ions and are found as monatomic atoms in nature .
The only group of elements that DO NOT form ions and are found as monatomic atoms in nature are the: noble gases.
What are noble gases?The noble gases are a group of chemical elements with comparable qualities; under normal conditions, they are all odourless, colourless, monatomic gases with very minimal chemical reactivity. Historically, they were also known as inert gases and aerogens. Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radioactive radon are the six naturally occurring noble gases (Rn).
Oganesson (Og) is a highly radioactive element created synthetically. Although the IUPAC has included oganesson since "group 18" and "noble gas" have been used interchangeably, oganesson may not be appreciably chemically noble and is projected to deviate from the norm and be reactive due to relativistic effects. Its chemistry has not yet been studied due to the single known isotope's relatively brief 0.7 ms half-life.
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Sandra is riding a water slide at her favorite water park. At the top of the slide,
she has 5,000 J of gravitational potential energy. After a few seconds, she has
1,928 J of gravitational potential energy. What is her kinetic energy at this point,
in J?
Answer:
3072J
Explanation:
At all points through her slide, it is important to reiterate that energy is always conserved.
Kinetic energy is the energy due to the motion of a body.
Potential energy is the energy due to the position of a body.
Based on the law of conservation of energy, energy is neither created nor destroyed but simply transformed from one form to another.
So;
At all points:
Total energy = Potential energy + Kinetic energy
Since the initial energy = 5000J which is the potential energy
This is the total energy within the system as the kinetic energy at this point is 0;
After a few seconds, the potential energy is 1928J;
Kinetic energy = Total energy - potential energy = 5000J - 1928J
Kinetic energy = 3072J
x ray are harmful for human health
false. when you get an xray all the doctors are doing is taking a pic of your bones.
A student rides a bicycle for 15 miles in 3 hours. What is the student's speed? What else would you need to know for the velocity?
Answer:
5 miles per hour
Explanation:
if you divide 15 by 3 you get 5, therefore the student is going 5 miles per hour.
Julio was standing at the Om line and ran west to the 50m line in 5s. What
was Julio's velocity?
O 10 m/s east
O 10 m/s west
O 250 m/s east
250 m/s west
HELP PLS MARKING BRANLIST 100 pts TAKING TEST RN
An airplane went from 120 m/s to 180 m/s in 4.0 seconds. What was its acceleration?
45 m/s2
15 m/s2
60 m/s2
30 m/s2
Answer:
15 m/s^2 The first thing to calculate is the difference between the final and initial velocities. So 180 m/s - 120 m/s = 60 m/s So the plane changed velocity by a total of 60 m/s. Now divide that change in velocity by the amount of time taken to cause that change in velocity, giving 60 m/s / 4.0 s = 15.0 m/s^2 Since you only have 2 significaant figures, round the result to 2 significant figures giving 15 m/s^2
Explanation:
Velocity is speed in a given
• space
• direction
• number
• problem
Peaks in standing wave are called
Answer:
Antinode
Explanation:
The antinode is a point along the wave that has the greatest maximum velocity in the y-direction.
If the wavelength of a wave is quadrupied then what happens to the frequency of the wqve(Assume speed is constant)
Answer:
What happens to the wavelength of a wave if you double the frequency?
If the frequency of a wave is increased, what happens to its wavelength? As the frequency increases, the wavelength decreases. 2. If the frequency is doubled, the wavelength is only half as long.
Explanation:
How much power does an Ox pulling a plow 20 m cross a field, exerting 120J of work over a period of 15 s?
Answer:
8W
Explanation:
Given parameters:
Distance covered = 20m
Work done = 120J
Time = 15s
Unknown:
How much power does the Ox exerts = ?
Solution:
Power is the rate at which work is being done
Power = [tex]\frac{Work done }{time}[/tex]
Power exerted by ox = [tex]\frac{120}{15}[/tex] = 8W
The ultrasound is reflected from the seafloor back to the submarine.
Use the correct answers below to complete the sentence.
A. Half
B. The same as
C. Twice
The total distance the ultrasound pulse travelled is......... the distance to the sea floor.
Answer: c
Explanation:
The total distance the ultrasound pulse travelled is, twice the distance of the sea floor
Because it went back and forth
A 1.5 kg ball is thrown at 10 m/s. What is the ball's momentum?
Answer:
[tex]\boxed {\boxed {\sf 15 \ kg*m/s}}[/tex]
Explanation:
Momentum is the product of mass and velocity.
[tex]p=m*v[/tex]
The mass of the ball is 1.5 kilograms and the velocity is 10 meters per second.
[tex]m= 1.5 \ kg \\v= 10 \ m/s[/tex]
Substitute the values into the formula.
[tex]p= 1.5 \ kg* 10 \ m/s[/tex]
Multiply.
[tex]p=15 \ kg*m/s[/tex]
The momentum of the ball is 15 kilogram meters per second.
Answer:
15 kg m/s
Explanation:
[tex]p = mv \: = 1.5 \times 10 = 15 \: kgm {s}^{ - 1} [/tex]
A(n) ________________________ is a molecule that is soluble in both polar and nonpolar solvents.
Answer: ethanol which will dissolve in both water (a polar solvent) and gasoline (a non-polar solvent)
Explanation:
According to the concept of solubility, ethanol is a molecule which is soluble in both polar and non-polar solvents.
What is solubility?
Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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How much work is done on a small car if a 1000 N force is exerted to move it 75
Answer:
75000J
Explanation:
Given parameters:
Force applied on the car = 1000N
Distance moved = 75m
Unknown:
Work done = ?
Solution:
The work done by a body is the force applied to move it through a particular distance.
So;
Work done = Force x distance
Therefore;
Work done = 1000 x 75 = 75000J
What causes water to move from the liquid part of the hyrdrosphere to the cyrosphere?
Answer:
When the liquid moves through the hydrosphere, the water collects into a cloud. When it falls to the earth, turning into snow and sleet collecting in rivers and lakes.
Explanation:
Hope that helps
Answer:
The frozen part of the hydrosphere has its own name, the cryosphere. Water moves through the hydrosphere in a cycle. Water collects in clouds, then falls to Earth in the form of rain or snow. This water collects in rivers, lakes and oceans.
please answer and fast i am in a test
Answer:
Online means connected to a network.
Credible means reliable or trustworthy
Cite means to quote from an article or book.
Where on the electromagnetic spectrum can you find infrared waves? Compare to gamma, x-ray, ultraviolet, and light waves.
Answer:
Infrared, Visible light, UV light, X-ray, gamma
Explanation:
When a golf club hits a 0.0459 kg ball at rest, it exerts a 2380 N force for 0.00100 s. What is the speed of the ball afterwards? (Unit = m/s)
Answer:
51.85m/s
Explanation:
Given parameters:
Mass of ball = 0.0459kg
Force = 2380N
Time taken = 0.001s
Unknown:
Speed of the ball afterwards = ?
Solution:
To solve this problem, we use Newton's second law of motion:
F = m x [tex]\frac{v - u}{t}[/tex]
F is the force
m is the mass
v is the final velocity
u is the initial velocity
t is the time taken
2380 = 0.0459 x [tex]\frac{v- 0}{0.001}[/tex]
0.0459v = 2.38
v = 51.85m/s
Answer:
2.38
Explanation:
F = dp/dt --> dp = F*dt ---> p = F*t if F is constant over time so
p = 2380N* 0.001 s = 2.38 kg-m/s
can anyone help with this?
The potential energy of a watermelon is 15.0 J. The watermelon is 3.0 m high. What is the mass of the watermelon?
g = 9.8 m/s2
Answer:
m = 0.51[kg]
Explanation:
Potential energy is defined as the product of mass by gravity by height.
[tex]E_{pot}=m*g*h[/tex]
where:
Epot = potential energy = 15 [J]
m = mass [kg]
g = gravity acceleration = 9.8 [m/s²]
h = elevation = 3 [m]
Now replacing:
[tex]E_{pot}=m*g*h\\15=m*9.8*3\\m = 0.51[kg][/tex]
help please fast + i dont want an answer from g**gle .
What is the force cause by an elephant of 4054 kg moving at 5.5 m/s2?
F = ma
A) 700 Newtons
B) 22,000 Newtons
C) 740 Kg x m/s2
D) 22,297 kg
Answer:
C
Explanation:
A hockey puck slides to a stop on ice. The coefficient of friction between the puck and
the ice is 0.026. What is the puck’s acceleration?
Answer:
Explanation:
The puck slides on the ice . Coefficient of sliding friction μ = .026
Limiting frictional force = μ R
R is reaction force of the surface .
R = mg
Friction force = μ mg
deceleration = μ mg / m
= μ g
= .026 x 9.8 = .2548
= 0.26 m /s².
Which terms describe the purpose of antennas on devices that use radio waves?
transmit and receive
modify and amplify
amplify and receive
modify and transmit
Which terms describe the purpose of antennas on devices that use radio waves?
Answer:
transmit and receiveExplanation:
Hope it helps:)
#CarryOnLearning
Answer:
Transmit and receive (A)
Explanation:
On Edge