Answer:
Frequency, [tex]f=5.24\times 10^{14}\ Hz[/tex]
Explanation:
It is given that, a yellow laser provides 210 kJ/mol of energy to excite electrons in a sample. We need to find the frequency of this light.
Energy, E = 210 kJ/mol
i.e.
[tex]E=210\ \dfrac{kJ}{mol}\\\\E=210\times 1000\ \dfrac{J}{mol}\\\\E=\dfrac{21\times 10^4\ J/mol}{6.022\times 10^{23}\ /mol}\\\\E=3.48\times 10^{-19}\ J[/tex]
The energy used to excite electrons is given by :
[tex]E=hf\\\\f=\dfrac{E}{h}\\\\f=\dfrac{3.48\times 10^{-19}}{6.63\times 10^{-34}}\\\\f=5.24\times 10^{14}\ Hz[/tex]
A 1.200 kg car travels at 20 m/s. What is its momentum? P=mv
A)24000 kg m/s
B)14000 kg m/s
C)8000 kg m/s
D)1220 kg m/s
Answer:
A
Explanation:
Answer:
Answer A
Explanation:
P = mv
P = 1200 kg × 20 m/s
P = 2400 kg m/s
So the answer would be A
Which of the following is not a way that a U-235 atom could fission?
235
92
U+
1
0
n →
144
Bat
56
90
36
Kr+2
n+energy
0
O A.
94
235
92
U+
0-
n →
141
52
Te+
Zr+2
n+energy
0
40
0
B.
1
139
1
235
92
U+
n →
Te +
94
Zr +3
40
n+energy
0
52
0
C.
1
1
235
92
n+energy
U+
141 92
Bat Kr +3
56
36
n->
0
0
O D.
SUBMIT
Answer:
I think.the frist one
Explanation:
because that only one that make sense to me
A way that a U-235 atom could not fission is 94
235U92 + 0n -1 → 141Te52 + 40Zr+ 0n2 +energy
What is nuclear fission?When the slow moving neutrons are bombarded with the heavy radioactive nuclei, the product is the more number of neutrons are produced with the large amount of energy. This multiplying process is called nuclear fission.
The amount of energy produced in nuclear fission reaction is again used in the next fission process.
The neutron has no charge and has a rest mass. While reacting the U-235 atom with neutron, more number of neutrons are released.
Thus, the correct option is A.
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What was the key element that caused Venus and Earth to have different environments?
a.) the way carbon is stored
b.) the presence of humans
c.) water and the oceans
d.) how close they are to the sun
Option D because the temperatures there are like 800 degrees Fahrenheit which means it is enough o melt lead so that's the key element that caused Venus and earth to have different environments because energy is key to life.
Using the velocity versus time graph, what was the average acceleration of the object for the first five seconds?
A) 4 m/s/s
B) 5 ms/s
C) 10 m/s/s
D) 20 m/s/s
Answer:
4 m/s²
Explanation:
a = Δv / Δt
a = (20 m/s − 0 m/s) / (5 s − 0 s)
a = 4 m/s²
Acceleration of a moving body is the rate of change of its velocity. The average acceleration of the object for the first five seconds is 4 m/s².
What is acceleration?Acceleration of a body is the rate of change of its velocity. Acceleration is a vector quantity and have both magnitude and direction. The change in magnitude or direction or both of velocity changes results in acceleration of the object.
Acceleration is the ratio of change in velocity to the change in time. Thus, it can be written as :
a = ΔV/ΔT
Here, the time changes from 0 to 5 seconds and the velocity changes from 0 to 20 m/s. Hence, the average acceleration is calculated as follows:
a = 20 - 0 m/s / ( 5 - 0 s)
= 4 m/s²
Therefore, the average acceleration of the object in first 5 seconds is 4 m/s².
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HELP HELP HELP HELP HELP HELP!!!!!!
Barry is 62 years old. He runs every single day. His BMI is 15. He would like to gain weight, and increase muscle in his upper body, chest, and back.
what exercise should he do?
Answer:
.He shouldn't eat:
1.Sugar
2.Fast food
3.Fat
Exercise:
1.Heel touches while lying on the ground
2.Abdominal crunches
3.V ups
3.Planks
R1 -4.00
M
- V = 12.0 V
Т.
1. Using Ohm's Law, Calculate the current / flowing
through the circuit in Figure 1.
Show all work.
Answer: V = 12.0 V
Explanation:
WILL GIVE BRAINIEST TO CORRECT
Calculate the frequency of a wave that is traveling at a speed of 3.0 m/s and has a wavelength of 1.2 m.
Frequency = speed / wavelength
Frequency = (3 m/s) / (1.2 m)
Frequency = 2.5 /s
That's 2.5 Hz.
Which law says that the induced voltage is directly proportional to the magnetic flux? A. Ohm’s Law B. Faraday’s Law C. Ampere’s Law D. Gauss’ Law E. Edison’s Law
Answer:
The correct answer is B) Faraday's Law
B. is the correct answer, ur now 2 grades higher bro
Help Plzzzzzzz I need help ASAP!!!!!!!
Answer: A spanner with a long handle
Explanation: The use of a spanner for opening the nut of a simple machine will employ the principle of moment.
The force apply to the nut is considered as load while the force applied to the spanner is considered to be effort.
Before the nut can be opened, the effort must overcome the load.
Since moment is the product of a force and the perpendicular distance, the spanner with a long handle will produce a higher moment.
Therefore, a spanner with a long handle will be preferred.
a. Does this graph represent an endothermic or an exothermic reaction? Explain your answer.
b. What is the enthalpy change, ΔH, for this reaction? Show your work.
c. What is the activation energy, Ea, for this reaction? Show your work.
2. In a particular chemical reaction, the energy of the reactants is 30 kJ and the energy of the products is 5 kJ. The maximum energy of the system is 40 kJ.
a. Sketch a potential energy diagram for this reaction. Make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.
b. What is the activation energy for this reaction?
c. What is the enthalpy change for this reaction?
d. Is this reaction endothermic or exothermic? Explain your answer in two ways: first, using the energy values, and second, by referring to the shape of the graph.
3. The coating on the head of a match is highly flammable. When it burns, it releases a great deal of energy. However, before the match can burn, it must gain a small amount of energy from a spark. That spark is typically produced by striking (rubbing) the match head against a rough surface. Sketch and describe a potential energy diagram that represents the striking and burning of the match. Remember to label the diagram with the energy changes that occur. Your answer must include the potential energy diagram and a written description. (Note: you do not have to use actual energy values.)
Answer:
Exothermic reaction
Explanation:
Exothermic reaction relases energy while endothermic absorbs energy.
Answer:
eeeeeeeeeee
exothermic
This is how sodium appears in the periodic table. An orange box has N a at the center and 11 above. Below it says sodium and below that 22.99. A blue arrow points to 22.99. The arrow is pointing to sodium’s number of neutrons. number of valence electrons. combined number of neutrons and protons. combined number of electrons and protons.
Answer:
I believe it is answer C.
Explanation:
Answer:
C: atomic mass
Explanation:
Which question could be answered using the scientific method?
Why does my dog like to sit on the sofa?
Would Mars be a fun place to live?
Are butterflies happy?
Do vitamins help people stay healthy?
Answer:The vitamins one.
Explanation:
Answer:
d. do vitamins help people stay healthy
Explanation:
flvs
A baby cow has a mass of 100 kg and chases its mother at a speed of 0.5
m/s. What is the magnitude of its momentum?
Answer: 50 kgm/s
Explanation:
Given that the
Mass M = 100kg
Velocity V = 0.5 m/s
Momentum can be defined as the product of mass and velocity. That is,
Momentum = MV
Substitute the values of M and V into the formula
Momentum = 100 × 0.5
Momentum = 50 kgm/s
Therefore, the magnitude of momentum is 50 kgm/s
Answer:
50 kg-m/s
Explanation:
hii:) the last 2 paragraphs are confusing, I thought mass doesn’t change?
Answer:
It's true that mass doesn't change
but because of difference in gravitational force on earth and moon, the scale used for weighing weight gives different reading. If we use the scale used for measuring the mass then the reading will be same. I think this was confusing you
A circuit has a voltage drop of 60.0 V across an 80.0 resistor that carries a current of 0.750 A. What is the power used by the resistor? Use P = VI. A. 60.0 W B. 45.0 W C. 4800.0 W D. 2.00 W
45.0 W is the answer
What are the answers please help
Answer:
a.) The main scale reading is 10.2cm
b.) Division 7 = 0.07
c.) 10.27 cm
d.) 10.31 cm
e.) 10.24 cm
Explanation:
The figure depicts a vernier caliper readings
a.) The main scale reading is 10.2 cm
The reading before the vernier scale
b.) Division 7 = 0.07
the point where the main scale and vernier scale meet
c.) The observed readings is
10.2 + 0.07 = 10.27 cm
d.) If the instrument has a positive zero error of 4 division
correct reading = 10.27 + 0.04 = 10.31cm
e.) If the instrument has a negative zero error of 3 division
correct reading = 10.27 - 0.03 = 10.24cm
Michal has a T-shirt that glows in the dark he holds his T-shirt up to light source and then turns off the light his T-shirt continues to glow. Explain this phenomenon?
Answer: Residual fluorescence.
Explanation:
The T-shirt is first kept in the light source for 10 to 15 minutes or more and then when it is taken to a dark place it glows.
This phenomenon is known as residual fluorescence.The t-shirt contains phosphors. It is a visible light which is seen after it is energized.
When the T-shirt is under a light source it is basically in a charging mode and then after some time in the dark it glows due to the phosphors mixed in the fabric.
This is also in some of the toys,watches and other stuffs that glows in the dark.
PLEASE HELP 50 pts + brainliest. 3. A laser light travels from air (n=1) through water (n=1.33), and then a piece of glass (n=1.55). The light first enters the water at an angle of 25.0 degrees (from air to water). Draw a diagram. Use Snell’s Law to find the angle of refraction in the water and then in the glass. I don't know how to do this.
Answer: the angle of refraction in the water is 34.2 degrees and then in the glass is 41 degrees approximately
Explanation:
A laser light travels from air (n=1) through water (n=1.33), and then a piece of glass (n=1.55).
If the light first enters the water at an angle of 25.0 degrees (from air to water). That means
The incident angle = 25 degrees
Using Snell' law
n(air)/n(water) = sin 25/sin R
Where R is the angle of refraction
1/1.33 = sin 25/sin R
Make sin R the subject of formula
Sin R = sin 25 / 0.7518
Sin R = 0.5620
R = sin^-1(0.5620)
R = 34.2 degrees
This angle will be an incident angle when the light is travelling from the water to glass. Using Snell law agains,
1.33/1.55 = sin 34.2/sin R
Cross multiply
1.33 sin R = 0.87122
Make R the subject of formula
Sin R = 0.87122/1.33
Sin R = 0.6550
R = sin^-1(0.6550)
R = 40.9 degrees
Therefore, the angle of refraction in the water is 34.2 degrees and then in the glass is 41 degrees approximately.
Find the attached file for the figure
A geologist tests a rock containing calcium oxide by reacting it with hydrochloric acid. Water and calcium chloride form. Which bonds break?
H–O bonds in water and Ca–Cl bonds in calcium chloride
Ca–Cl bonds in calcium chloride and H–Cl bonds in hydrochloric acid
Ca–O bonds in calcium oxide and H–O bonds in water
Ca–O bonds in calcium oxide and H–Cl bonds in hydrochloric acid
Answer:
The following bonds breaks:
Ca–O bonds in calcium oxide and H–Cl bonds in hydrochloric acid
Explanation:
When calcium oxide reacts with hydrochloric acid, water and calcium chloride are formed. The reaction is given as:
CaO + 2HCl ⇒ CaCl₂ + H₂O
Where
CaO has an ionic bond between Ca and O because Ca is a metal and O is a non-metal, which results in complete transfer of electrons from calcium to oxygen.
HCL is usually in a gaseous state which has a covalent bond between H and Cl, but HCL acid means HCL in the presence of water, which will have an ionic bond.
Under the given reation, both of these ionic bonds break to form new ones
Which of the following can be studied by science?
O A. The mass of a dwarf planet
OB. The popularity of a new video game
O C. The name of a hurricane
O D. The beauty of the Grand Canyon
People began to study classical thought wing the Renaissance to
Answer:
Explanation:
to better themselves and to be good educated people
Answer:
A. better themselves.
Explanation:
just did test edg2020
2. Using examples to describe each term, differentiate
among average, instantaneous, and uniform velocity.
Answer: find the answer in the explanation
Explanation:
Average velocity is the average value of magnitude of initial velocity and final velocity.
If U = initial velocity and V = final velocity, then average velocity can be expressed as
Average velocity = ( U + V )/2
A vehicle who takes 60 minutes to cover 30 miles north and then 30 miles south and end up at the same place, has an average speed of 60 miles divided by 60 minutes, or 1 mile per minute.
Instantaneous velocity is the distance covered in a specific direction per time taken. Instantaneous velocity can be expressed as
Velocity = displacement/ time.
Uniform velocity occurs when we have a constant velocity. That is, when velocity does not change. When a vehicle travels in equal distances in equal intervals of time.
If you place small pieces of tissue paper near the balloon in Picture 2, they would probably stick to the
balloon. Explain why.
Answer:
The balloon has more negative charges than positive charges. The tissue paper has a neutral charge.The static electricity pulls on the tissue paper lifting it up.
A block with mass 0.470 kg sits at rest on a light but not long vertical spring that has spring constant 85.0 N/m and one end on the floor. A second identical block is dropped onto the first from a height of 4.40 m above the first block and sticks to it. What is the maximum elastic potential energy stored in the spring during the motion of the blocks after the collision?
Answer: elastic potential energy = 20.27 J
Explanation:
Given that the
Mass M = 0.470 kg
Height h = 4.40 m
Spring constant K = 85 N/m
The maximum elastic potential will be equal to the maximum kinetic energy experienced by the block.
But according to conservative of energy, the maximum kinetic energy is equal to the maximum potential energy experienced by the block of mass M.
That is
K .E = P.E = mgh
Where g = 9.8m/s^2
Substitutes all the parameters into the formula
K.E = 0.470 × 9.8 × 4.4
K.E = 20.27 J
Where K.E = maximum elastic potential energy stored in the spring during the motion of the blocks after the collision which is 20.27J.
The maximum potential energy stored in the spring during the motion of the blocks is 20.39 J.
The given parameters;
mass of the block, m = 0.47 kgspring constant, k = 85 N/mThe extension of the spring is calculated as follows;
[tex]F =kx\\\\mg = kx\\\\x = \frac{mg}{k} \\\\x = \frac{0.47 \times 9.8}{85} \\\\x = 0.054 \ m[/tex]
The maximum potential energy stored in the spring during the motion of the blocks is calculated as;
[tex]P.E = \frac{1}{2} kx^2 \ + mgh\\\\P.E = \frac{1}{2} (85)(0.054)^2 \ + \ (0.47)(9.8)(4.4)\\\\P.E = 20.39 \ J[/tex]
Thus, the maximum potential energy stored in the spring during the motion of the blocks is 20.39 J.
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Andrew Haber is an astronaut in space, far away from gravitational and frictional forces. He throws a tennis ball. The ball will:
A) come back to him
B) gradually come to rest
C) continue to move in a straight line with uniform velocity
D) come to rest abruptly
Answer:
the answer is C.
Explanation:
continue to move in a straight line with uniform velocity.
Andrew Haber is an astronaut in space, far away from gravitational and frictional forces. He throws a tennis ball. The ball will continue to move in a straight line with uniform velocity. The correct option is C.
What are gravitational and frictional forces?Gravity always pulls things down, whether it's a desk, a book, or a person. As a result, gravity pulls you down to the ground as you jump. But friction doesn't drag things down. But friction doesn't drag things down.
The direction of the push used to move the body is the opposite of the direction of friction. Because of the increased force of friction, sliding a body across a surface becomes more difficult when gravity is strong.
Therefore, the correct option is C) continue to move in a straight line with uniform velocity.
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Calculate the frequency if the time between two wave crests is 5
seconds?
Answer:
Wave frequency can be measured by counting the number of crests or compressions that pass the point in 1 second or other time period. The higher the number is, the greater is the frequency of the wave.
hope this helps u
Answer:
0.2 Hz
Explanation:
Write a hypothesis about the effect of the angle of the track on the acceleration of the cart. Use the "if . . . then . . . because . . .” format and be sure to answer the lesson question: "How does an object's position and velocity change as the object accelerates?”
Answer:
Sample Response: If the angle of the track increases, then the acceleration of the cart increases because a greater track angle increases the cart's velocity.
Explanation:
because.
Is this a scientific model? Use complete sentences to explain why or why not.
Answer:
it is a scientific model if you want to research where in the world is vegetation located.
Help||| When a stringed instrument is out of tune, the player with tighten or loosen the string. If the instrument is initially flat, should they tighten or loosen the string? In the context of this experiment, explain your reasoning.
Answer:
So if its regular, you would always tighten it. Here's the reasoning:
"When you lower the pitch by releasing tension, there might be slack in the gears in the tuning machines, which might make the string go below the intended pitch. By going further down and approaching the target note from below, there will be force applied to the gears and when you've reached the correct pitch the gears have less potential to move. So your teacher is correct."
Therefore the answer is TighteningAnswer: So if its regular, you would always tighten it. Here's the reasoning: "When you lower the pitch by releasing tension, there might be slack in the gears in the tuning machines, which might make the string go below the intended pitch.
Explanation:
"When you lower the pitch by releasing tension, there might be slack in the gears in the tuning machines, which might make the string go below the intended pitch. By going further down and approaching the target note from below, there will be force applied to the gears and when you've reached the correct pitch the gears have less potential to move. So your teacher is correct."
Besides air pollution, the student was concerns about water/ocean pollution. They heard many recent issues of too much plastic in the ocean and other pollutants in the water. The pie chart below provides data on the sources and amounts of different pollutants entering the oceans.
first picture
The student read a news article that discussed the increase in amount of pollutants entering oceans and washing up on shores. The article included this image.
second picture
pick the answer
The greatest reduction in pollutants entering the ocean could be achieved if it were possible to reduce farm runoff/transportation/air pollutants/sewage/litter/ orindustry waste.
Answer:
Sewage
Explanation:
It has the greatest percentage out of the pie chart.