Answer:
Let N0 be the initial atoms of Be11
N0 / 2^1 = N0 / 2 Number of Be11 after 1 half-life
N0 / 2^2 = N0/ 4 Number of Be11 after 2 half-lives
30/13.81 = 2.17 half lives
N0 / 2^2.17 = N0 / 4.51 = .222 N0 or 22.2 % of atoms remain
The percentage of the initial sample that will remain after 30.0 s is 22.2 % of atoms remain.
What is half-life?A half of existence is the duration required for something to reduce in size by half. The phrase is most frequently used in reference to radioactive decay, which takes place as unstable atomic particles weaken. There are 29 known factors that can operate in this way.
Every chemical has a unique half-life. Since carbon-10, for instance, has a half-life of only 19 seconds, it is impossible for this isotope to be found in nature.
Let No of the initial atoms of Beryllium-11
No / 2¹ = N0 / 2 Number of Be11 after 1 half-life
No / 2² = N0/ 4 Number of Be11 after 2 half-lives
30 / 13.81 = 2.17 half lives
No / 2²·¹⁷ = N0 / 4.51 = .222 N0 or 22.2 % of atoms remain
Therefore, the percentage of the initial sample will remain after 30.0 s is 22.2 %.
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What is the period of a sound wave with a frequency of 20Hz?
As shown in the diagram below, a 1 kg rock tied to a rope is
swung by a boy. This rock has a constant speed of 5 m/s,
and the length of the rope is 1 m. The rock's angular
momentum is
Answer:
Explanation:
Angular momentum has a formula of L = mvr. Fillingin:
L = (1.0)(5.0)(1.0)
L = 5.0 kg*m/s
1
The distance between objects, along with the masses of the object, affect the gravitational force between the objects. Which
statement is TRUE according to Newton's law of universal gravitation?
O When the masses of objects increase, gravitational force decrease
O When the distance between objects increases, gravitational force decreases.
O When distances between objects decreases, gravitational force decreases
O When the masses of objects decrease, the distance between objects decreases.
Every object in the universe attracts every other object with a force along a line joining them. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers of mass.
Which is a valid ionic compound?
sodide chlorine
sodium chlorine
sodium chloride
sodide chloride
Answer:
sodium chloride
Explanation:
Sodium chloride is an ionic compound. The ions of the sodium chloride compound is sodium ion and chloride ion. The sodium ion is cation while the chloride ion is an anion. Sodium chloride is a very stable compound because of the mutual attraction of oppositely charged ions.
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A spring with a spring constant of 2.5 N/m is stretched by 0.2 m. What is the potential energy in the spring
Answer:
Explanation:
PE = [tex]\frac{1}{2}k[/tex](Δ[tex]x^2[/tex])
where k is the spring constant and Δx is the displacement of the spring when an object is hung from it. Plugging in:
[tex]PE=\frac{1}{2}(2.5)(.2^2)[/tex] which gives us
PE = .05 J
Physicist ____ was found to have completely made up some of the data on which his astounding discoveries were made.
Answer:
Jan Hendrik Schön I believe
Which statement best describes the Sun Earth-Moon system?
Answer:
A
Explanation:
A. The Moon orbits the Earth, and the Earth-Moon system orbits the Sun
B. The Earth and Moon both orbit the Sun separately
C. The Sun orbits the Earth-Moon system
D. The Moon revolves around Earth but not the Sun
Electrical current is the flow of ____________
A) helium
B) protons
C) atoms
D) electrons
How much voltage is required to make 0.56 A flow through a 72-ohm resistance? [V = I x R]
A)48 V
B)36 V
C)40 V
D)52 V
WILL GIVE BRAINLIEST!!!
Solution :
A) Electric current is the flow of electrons .
B) We know, by ohm's law :
V = I × R
Putting given values in above equation, we get :
V = 0.56 × 72 V
V = 40.32 V
Hence, this is the required solution.
walk done in units time is called
Answer:
Explanation:
work done per unit time is caleed power.it's SI unit is watt.it depends upon time.
Electronic flash units for camera contain a capacitor for storing the energy used to produce the flash. In one such unit, the flash lasts for 1675s with an average light power output of 2.70 x 105 W . (a) If the conversion of electric energy to light is 95% efficient ( the rest of the energy goes to thermal energy), how much energy must be stored in the capacitor for one flash
Answer:
420J
Explanation:
Power is the time rate of change in energy. Power is the ratio of energy to time. The S.I unit of power is in watts.
Given that the flash lasts for 1/675 s, power output is 2.7 * 10⁵ W. Hence:
Power = Energy / time
Substituting:
2.7 * 10⁵ W = Energy / (1/675)
Energy = 2.7 * 10⁵ W * 1/675 = 400J
Therefore the energy emitted as light is 400J.
Since the conversion of electric energy to light is 95% efficient, hence the energy stored as electrical energy is:
Energy(capacitor) = 5% of 400J + 400J = 0.05*400 + 400
Energy(capacitor) = 420J
Mark was traveling at 40 mph on a road with a drag factor of 0.85. His brakes were working at B0o/o efficiency. To the nearest tenth of a foot, what would you expect the average length of the skid marks to be if he applied his brakes in order to come to an immediate stop
The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
The given parameters:
Speed of Mark, v = 40 mphDrag factor, F = 0.85Working efficiency of the brake, n = 80%The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is calculated as follows;
[tex]v = \sqrt{30 D fn} \\\\40 = \sqrt{30 \times D \times 0.85 \times 0.8} \\\\40 = \sqrt{20.4 D} \\\\40^2 = 20.4D\\\\1600 = 20.4 D\\\\D = \frac{1600}{20.4} \\\\D = 78.43 \ ft[/tex]
Thus, the average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
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What would make oppositely charged objects attract each other more?
increasing the positive charge of the positively charged object and increasing the negative charge of the
negatively charged object
decreasing the positive charge of the positively charged object and decreasing the negative charge of the
negatively charged object
increasing the distance between the positively charged object and the negatively charged object
maintaining the distance
tance between the positively charged object and the negatively charged object
Hurry I need answers quick I’m timed
Answer:
A). Increasing the positive charge of the positively charged object and increasing the negative charge of the negatively charged object.
Explanation:
The two objects possessing opposite or unlike charges attract one another due to the electromagnetic force between the electrons, as well as, protons in order to develop ionic lattices.
As per the question, the objects having unlike charges would attract one another more when we 'escalate the positive charge of the object having a positive charge and enhance the negative charge of the object possessing negative charge.' This will lead the atoms that are losing electrons to be positively(+ve) charged and the atoms gaining electrons to be negatively
(-ve) charged. Thus, the electromagnetic force among them increases and a stronger ionic network develops leading them to attract each other more. Hence, option A is the correct answer.
Answer:
The person above me is wrong the answer is actually B
Explanation:
I put his/her answer and got it wrong and it showed me theat the answer is b not a
a 5 kg block is on a frictionless surface. A 15 N force is applied to the block in a direction parallel to the surface. what is the acceleration of the block?
A. 3 m/s^2
B. 10 m/s^2
C. 20 m/s^2
D. 75 m/s^2
Answer:
D 75
Explanation:
I'm pretty sure it's just 5x15=75
Answer:
the answer would be 3/s^2
Explanation:
because all u have to do is divide 15 by 5 and u would get 3
What would happen to the distance between the bright fringes produced by a diffraction grating if the entire interference apparatus (light source, grating, and screen) were immersed in water
Answer:
Since the wavelength would be reduced by the factor of N where N is the index of refraction, fringes would be be closer to one another.
(Similar to the difference of fringes of red light and blue light.)
what is the power of a student that has done a work of 10 joules in 10 seconds
Answer:
1 Watt
Explanation:
P=W/t
P=10/10
P=1 Watt
58
74
3 points
A hummingbird beats its wings up and down with a frequency of 100 Hz. What is the period of the hummingbirds flaps? (D
YOUR ANSWER)
59
Answer:
T = 0.01 s
Explanation:
Given that,
The frequency of the beats of a hummingbird, f = 100 Hz
We need to find the period of the hummingbirds flaps. Let the time is t. We know that the relation between frequency and time period is given by :
T = 1/f
Put all the values,
T = 1/100 = 0.01 s
So, the time period of the humming bird is 0.01 s.
I WILL MARK YOU THE BRAINLIEST NO LINKS
What type of friction is acting on the airplane?
sliding friction
static friction
fluid friction
rolling friction
Answer:
I believe it's sliding friction.
Explanation:
A skipper on a boat notices wave crests passing the anchor chain every 6.0 seconds. The skipper estimates the distance between crests at 30.0
m. What is the speed of the water waves?
Explanation:
given Time Period = 5 Sec
Amplitude = 1m, Wave length = 15 m
using time period = 1/ frequency , Frequency = 1/5 cycles per sec = 0.2 sec = 12 per min
wave speed= Frequency * Wave length
speed = 0.2*15 = 3m/s
A 15-watt bulb is connected to a circuit that has a total of 60. Ω of resistance. How many electrons are passing through that bulb every second?
Answer:
3.2075*10^16
Explanation:
Q=P/V just search up a converter and youll get 30V and so you do 15/30 which is a half and a single coulomb is 6.415*10^16 so you half it. I belive this is correct if you dont belive me wait for someone else smarter to answer and compare.
G.P.E = weight (n) x height (m). 2 identical twins are skiing down 2 different slopes. one is 1000m high, the other is 1500 m high. the twin at 1000m weighs 150 N. the other twin weighs 100 N. which twin has the most P.E before they begin skiing?
Answer:
I don't know i really I'm sorry I wish I could help
Suppose that Joe and Jim are twins and :
________________________________
Joe :
Height = 1000 m
==》 PE = 150 × 1000
Weight = 150 N
==》 PE = 150,000 j
_________________________________
Jim :
Height = 1500 m
==》PE = 100 × 1500
Weight = 100 N
==》PE = 150,000 j
______________________________
As u can see Joe and Jim has equal PE before they begin skiing .
difference between acceleration due to gravity and gravity
Answer:
The gravitational force between earth and any object is known as gravity.
...
Describe how to determine the thickness of a sheet of a paper without a caliper.
Answer:
Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.
In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.
Answer:
Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.
In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.
Explanation:
A 56.6-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.517 and 0.260, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed
Answer:
Explanation:
Magnitude of frictional force = μ mg
μ is either static or kinetic friction.
To start the crate moving , static friction is calculated .
a ) To start crate moving , force required = μ mg where μ is coefficient of static friction .
force required =.517 x 56.6 x 9.8 = 286.76 N .
b ) to slide the crate across the dock at a constant speed , force required
= μ mg where μ is coefficient of kinetic friction , where μ is kinetic friction
= .26 x 56.6 x 9.8 = 144.21 N .
on a proton is 1.6×10`¹⁹. how many protons are in one coulomb of charge
Answer: There are [tex]6.25 \times 10^{18}[/tex] protons present in one coulomb of charge.
Explanation:
Given: Charge on proton = [tex]1.6 \times 10^{-19} C[/tex]
It is known that the charge on a proton is equal to the charge present on an electron.
Formula used to calculate number of protons is as follows.
Q = ne
where,
Q = charge considered
n = number of protons
e = charge on electron or proton
Substitute the values into above formula as follows.
[tex]Q = ne\\1 C = n \times 1.6 \times 10^{-19} C\\n = 0.625 \times 10^{19}\\= 6.25 \times 10^{18}[/tex]
Thus, we can conclude that there are [tex]6.25 \times 10^{18}[/tex] protons present in one coulomb of charge.
Pop up spring Lab
Describe the energy conversion that took place. What energy was present just before the jump? What energy is present at its maximum height? What happens in between?
Draw bar charts of energy before the jump, while the spring toy is compressed and after the jump at the maximum height of its jump. Be sure to label each type of energy.
Answer:
I honestly don't know but that thing looks cool lol
You are given two converging lenses to build a compound microscope. Lens A has focal length 0.50 cm and lens B has focal length of 3.0 cm. Which one of the two lenses would you use for the objective
Answer:
The lens to be used for the objective is lens A
Explanation:
The objective of a compound microscope
The focal length of the lens used for the objective = 1/(magnification obtained)
The focal length of most modern is equal to the tube length
The range of sizes for the focal length of a microscope is between 2 mm and 40 mm
Therefore, the appropriate lens to be used for the objective of the compound is lens A that has a focal length of 0.50 cm = 5 mm
A table is moved using 60 N of force.
How far is the table moved if 900 J of work is done on the table?
960 m
840 m
15 m
0.06 m
Answer:
15m
Explanation:
W=f×s
[tex]s = \frac{w}{f} \\ s = \frac{900j}{60n} \\ s = 15m [/tex]
Given:
Force,
F = 60 NWork done,
W = 900 JWe know,
→ [tex]W = F\times s[/tex]
or,
→ [tex]s = \frac{W}{F}[/tex]
By putting the values, we get
[tex]= \frac{900}{60}[/tex]
[tex]= 15 \ m[/tex]
Thus the above response i.e., "Option c" is right.
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Please hurry Describe why electric currents can be dangerous
Answer:
Cardiac Arrest, burns, and nerve damage.
Explanation:
Basically, the main risk is cardiac arrest, caused by the electric current interfering with the normal operation of the heart muscle. Other possible damages are burns due to the electric energy vaporizing the water inside the cells, and nerve damage caused by excessive current through the nerves.
If a positively charged rod is brought near the knob of a positively charged electroscope, the leaves of the electroscope will...
A) converge, only
B) diverge, only
C) first diverge, then converge
D) first converge, then diverge
Answer:
B
Explanation:
if a positively charged rod is brought near the knob of a neutral electroscope, it will attract some electrons up from the leaves onto the knob. That process causes both of the leaves to be positively charged (excess protons), and the leaves will diverge.