Answers
the measure of how many a wave passes on a certain point in a certain time is
frequency
Related Questions
Before the development of quantum theory, Ernest Rutherford's experiments with gold atoms led him to propose the so-called Rutherford Model of atomic structure. The basic idea is that the nucleus of the atom is a very dense concentration of positive charge, and that negatively charged electrons orbit the nucleus in much the same manner as planets orbit a star. His experiments appeared to show that the average radius of an electron orbit around the gold nucleus must be about 10−1010−10 m. Stable gold has 79 protons and 118 neutrons in its nucleus.
What is the strength of the nucleus' electric field at the orbital radius of the electrons?
What is the kinetic energy of an electron in a circular orbit around the gold nucleus?
Answers
Answer:
a) F = -1.82 10⁻¹⁵ N, b) K = 9.1 10⁻¹⁶ J
Explanation:
a) To calculate the force between the nucleus and the electrons, let's use the Coulomb equation
F = k q Q / r²
as the nucleus occupies a very small volume compared to electrons, we can suppose it as punctual
let's calculate
F = 9 10⁹ (-1.6 10⁻¹⁹) (79 1.6 10⁻¹⁹) / (10⁻¹⁰)²
F = -1.82 10⁻¹⁵ N
b) they ask us for kinetic energy
let's use Newton's second law
F = m a
acceleration is centripetal
a = v² / r
we substitute
F = m v² / r
v = √ (F r / m)
v = √ (1.82 10⁻¹⁵ 10⁻¹⁰ / 9.1 10⁻³¹)
v = √ (0.2 10⁻¹⁶)
v = 0.447 10⁸ m / s
kinetic energy is
K = ½ m v²
K = ½ 9.1 10⁻³¹ (0.447 10⁸)²
K = 0.91 10⁻¹⁵ J
K = 9.1 10⁻¹⁶ J
A system of 18 electrons and 11 neutrons has a net charge of
Answers
Answer:
-28.8 × 10-19 C
If you want to make a strong battery, should you pair two metals with high electron affinities, low electron affinities, or a mix? Explain your answer.
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The anode needs to have a low electron affinity because it needs to readily release electrons, and the cathode needs to have a high electron affinity because it needs to readily accept electrons.
Please help willing to give brainliest
Electromagnetic waves do not require a medium to travel. Which one
below is an example of an electromagnetic wave?
1.ultraviolet waves
2.sound waves
3.water waves
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Answer:
sound water because sound is the most important electronic wave for water
PLEASE PROVIDE EXPLANATION FOR D AND E
THANK YOU!
Answers
Answer:
d) 14.1 m
e) 8.57 m/s
Explanation:
(a) There are three forces on the ball:
Normal force Fn pushing up,
Weight force Fg pulling down,
Kinetic friction Fk pushing left (resisting motion).
FBD is the correct free body diagram.
(b) Sum of forces in the y direction:
∑F = ma
Fn − Fg = 0
Fn = Fg
Sum of forces in the x direction:
∑F = ma
-Fk = ma
-Fn μk = ma
-mg μk = ma
a = -g μk
a = -(10 m/s²) (0.25)
a = -2.5 m/s²
(c) Sum of torques about the ball's center:
∑τ = Iα
Fk r = ⅖ mr² α
mg μk r = ⅖ mr² α
g μk = ⅖ r α
α = 5g μk / (2r)
α = 5 (10 m/s²) (0.25) / (2 × 0.2 m)
α = 31.25 rad/s²
(d) The velocity and angular velocity at time t is:
v = at + v₀
v = -2.5t + 12.0
ω = αt + ω₀
ω = 31.25t + 0
When the ball begins to roll without slipping, v = ωr.
-2.5t + 12.0 = (31.25t) (0.2)
-2.5t + 12.0 = 6.25t
12.0 = 8.75t
t = 1.37
The distance the ball moves is:
Δx = v₀ t + ½ at²
Δx = (12) (1.37) + ½ (-2.5) (1.37)²
Δx = 14.1 m
(e) v = at + v₀
v = (-2.5 m/s²) (1.37 s) + 12.0 m/s
v = 8.57 m/s
Answer:
a
Explanation:
on egde 2020
Assume you push a 20 kg child in a little red wagon with a force of 100 N. However, the dirt and rocks below the wheels
create a frictional force of 25 N. What is the acceleration on the wagon and child?
A. 1.25 m/s2
B.3.75 m/s2
C. 5 m/s2
D. 0.2 m/s2
Answers
Answer:
a
Explanation:
What determines the radiation that an electromagnetic wave emits?
Answers
As the chief design engineer for a major toy company, you are in charge of designing a loop-the-loop toy for youngsters. The idea is that a ball of mass m and radius r will roll down an inclined track and around the loop without slipping. The ball starts from rest at a height h above the tabletop that supports the whole track. The loop radius is R. Determine the minimum height h, in terms of R and r, for which the ball will remain in contact with the track during the whole of its loop-the-loop journey
Answers
Answer: h = 2.7 R - 1.7 r
Explanation:
normally, force is 0 at the top ;
-N - mg = - m v^2 / ( R - r )
-0 - mg = (- mv^2) / ( R-r )
mg = (mv^2) / (R - r)
g = v^2 / ( R - r ) ; ----------------equation 1
conservation of energy ;
ΔK + ΔP = 0 ;
1/2 I ω^2 + 1/2 m v^2 + mg ( h2 - h1 ) = 0 ;
0.5 * ( 2/5 ) m r^2 * ( v / r )^2 + 0.5 m v^2 + mg ( ( 2R - r ) -h ) = 0 ;
0.5 * ( 2/5 ) m r^2 * ( v / r )^2 + 0.5 m v^2 = mg ( - 2R + r + h ) ;
0.5 * ( 2/5 )r^2 * ( v / r )^2 + 0.5 v^2 = g ( - 2R + r + h ) ;
0.5 * ( 2/5 ) v^2 + 0.5 v^2 = g ( - 2R + r + h ) ;
[ 0.5 * ( 2/5 ) + 0.5 ] v^2 = g ( - 2R + r + h ) ;-------------equation 2
from equation 1 , v^2 = g ( R - r ), input in equation 2
[ 0.5 * ( 2/5 ) + 0.5 ] [ g ( R - r ) ] = g ( - 2R + r + h )
[ 0.5 * ( 2/5 ) + 0.5 ] [ ( R - r ) ] = ( - 2R + r + h )
0.7 ( R - r ) = h - 2R + r
0.7R - 0.7r = h - 2R + r
solve for h
h = 0.7R + 2R - 0.7r - r
h = 2.7 R - 1.7 r
if a bust starts to move and its velocity becomes 90 km after 8 seconds . calculate its acceleration answer it quick please
Answers
Answer:
a = 3.125 [m/s^2]
Explanation:
In order to solve this problem, we must use the following equation of kinematics. But first, we have to convert the speed of 90 [km/h] to meters per second.
[tex]90\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s} \\= 25 \frac{m}{s}[/tex]
[tex]v_{f} =v_{i} + (a*t)[/tex]
where:
Vf = final velocity = 25 [m/s]
Vi = initial velocity = 0
a = acceleration [m/s^2]
t = time = 8 [s]
The initial speed is zero as the bus starts to koverse from rest. The positive sign of the equation means that the bus increases its speed.
25 = 0 + a*8
a = 3.125 [m/s^2]
Pretty Easy question please answer only 20 minutes left:
A summary of the results of a scientific investigation is called a:
observation
research
hypothesis
conclusion
Answers
Answer:
D. Conclusion.
Explanation:
Please help me with this.
Answers
a negatively charged particle is attracted to: A) all particles that are located close by B)negatively charged particles C) positively charged particles D)only particles that are large
Answers
Answer:
The answer is C) Positively charged particles
Explanation:
Particles with the same charge are repelled by one another, while particles with different charges are attracted to one another.
Answer:
positively charged particles (c)
Explanation:
I got it right on Study Island
In the International Space Station which orbits Earth, astronauts experience apparent weightlessness because:_________
a) the astronauts and the station are in free fall towards the center of the Earth.
b) there is no gravity in space. the station is kept in orbit by a centrifugal force that counteracts the Earth's gravity.
c) the station's high speed nullifies the effects of gravity.
d) the station is so far away from the center of the Earth.
Answers
Answer:
a) the astronauts and the station are in free fall towards the center of the Earth
Explanation:
Weightlessness is only a sensation of zero weight, a body experiences when it is in free fall towards the center of the Earth, caused by lack of contact force on such body.
Weightlessness doesn't mean the object has zero actual weight, is just a sensation of no weight due to lack of contact force to produce upward reaction on the object which gives the real sense of ones weight.
Thus, the astronauts experience apparent weightlessness because:
a) the astronauts and the station are in free fall towards the center of the Earth.
If the efficiency of a machine is equal to 85% and the work input is 10.0 , what is the work output?
Answers
Answer:
8.5
Explanation:
to find efficiency take the ratio between the output and input
85/100=output/input
What type of energy transfer causes a sunburn?
A. Radiation, because particles of hot air move in space
B. Radiation, because electromagnetic waves transfer heat
C. Conduction, because hot air comes in contact with the skin
D. Conduction, because invisible light carries heat from the sun
If your right you get 100 points and a brainliest
Answers
Answer:
Hi!!
It should be A, ratation
(sorry that I didnt spell that write)
Have a great day!
To solve this we must be knowing each and every concept related to energy and its different types. Therefore, the correct option is option A among all the given options.
What is energy?In physics, energy is the capacity to accomplish work. It can be potential, kinetic, thermal, electric, chemical, radioactive, or in other forms.
There is also heat and work—energy inside the process of being transferred by one body to the other. Energy is always classified according to its type once it has been transmitted. As a result, heat transported could become thermal energy, whereas labor done may emerge as mechanical energy. Radiation is a t type of energy that transfer energy that causes a sunburn because particles of hot air move in space.
Therefore, the correct option is option A among all the given options.
To know more about energy, here:
brainly.com/question/29763772
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HELP!!! HURRY!!!!! 100 POINTS!!!!!!!!!
Answers
what happens at Point C is sublimation. the increase in temperature affects the Vapour pressure soon as you can see the curve is increasing with increasing pressure there is increase in temperature that is the sublimation Curve
Answer:
what happens at Point C is sublimation. the increase in temperature affects the Vapour pressure soon as you can see the curve is increasing with increasing pressure there is increase in temperature that is the sublimation Curve.
Predict the magnitude of force applied on you if you push against a tree with a force of 50 and directed to the
Answers
Answer: -50N
Explanation:
Newton's 3rd law says that for every force applied, there is an opposite force with equal magnitude. The person pushing on the tree will experience a force of -50N
A baseball player is running at a constant velocity on a level field and tosses a baseball straight up. When the ball comes back down, it will land
Answers
Answer:
]
Explanation:
What does Weber's Law about 'just noticeable differences' predict about how much someone has to change the brightness of a light before we can notice the difference? a. It depends on how bright the light was in the first place - the brighter it was, the less change is needed before we realize it. b. It depends on how long we have been looking at the light - the longer we have been looking, the more change is needed. c. It is always the same amount - 7 lux. d. It depends on how bright the light was in the first place - the brighter it was, the more change is needed before we realize it.
Answers
Answer:
answer A is the correct one
Explanation:
Weber's law states that "the smallest discernible change of a stimulus and proportional to the stimulus".
Applying this law to cases of optical intensity, the ratio must be
k = cte = ΔI / I
where ΔI is the variation of the intensity and I is the value of the intensity
In general, for humans, the constant is 0.15 for the rods and 0.015 for the cones of the retina.
When reviewing the answers, answer A is the correct one, since in order for the previous relationship to be maintained, the magnitudes must rise proportionally
- You travel by bus from Indianapolis to New York City which is 1100 miles away. With no stops, the trip took 11 hours. The average speed was...
Answers
Answer:
100 mph, or about 44.7 m/s
Explanation:
Average speed is [tex]\frac{distance}{time\\}[/tex].
After substitution, this is [tex]\frac{1100}{11}[/tex].
The average speed, therefore, reduces to 100 mph, or about 44.7 m/s.
give at least two similarities and differences among the terrestrial planets Mars Venus and Earth
Answers
Answer:
Answer is as follow:
Explanation:
With a distance of just 6,792 km, Mars is even smaller. And again, Venus would be almost Earth's double in terms of scale. It has 81 percent of the earth 's volume, while Mars has just 10 percent of the earth 's mass. Mars and Venus have very different ecosystems, and they are both very separate from Earth.
The day time temperature of Mercury is 800 F . What is Mercury’s temperature in Celsius and kelvin?
Answers
Answer:
In Celsius it is 426.667
In Kevin it is 699.817
Explanation:
re testing a new amusement park roller coaster with an empty car with a mass of 100 kg. One part of the track is a vertical loop with a radius of 12.0 m. At the bottom of the loop (point A) the car has a speed of 25.0 m/s and at the top of the loop (point B) it has speed of 8.00 m/s . You may want to review (Pages 203 - 212) . For related problemsolving tips and strategies, you may want to view a Video Tutor Solution of A vertical circle with friction. Part A As the car rolls from point A to point B, how much work is done by friction?
Answers
Answer:
-4530 J
Explanation:
Given that
Mass of the car, m = 100 kg
Speed of the car at point A, v1 = 25 m/s
Speed at point B, v2 = 8 m/s
Radius of the track, r = 12 m and with respect to the origin of the center of the track, we say that y1 = -12 at point A and y2 = 12 at point B
We also know that
W(total) = W(grav) + W(other) = K₂ - K₁
Work done by the gravitational force, W(grav) = -U(grav) = mgy1 - mgy2
Kinetic Energy, K = ½mv²
Adding all together, we have
½mv₁² + mgy1 + W(other) = ½mv₂² + mgy2
½ * 100 * 25² + 100 * 9.8 * -12 + W = ½ * 100 * 8² + 100 * 9.8 * 12
50 * 625 + 980 * -12 + W = 50 * 64 + 980 * 12
31250 - 11760 + W = 3200 + 11760
19490 + W = 14960
W = 14960 - 19490
W = -4530 J
how long will a speed boat cross a 2.o km lake with a speed of 40 km/hr
Answers
Explanation:
s=d/t
t= d/s
t= 2/40
t= 0.05 hr
A family is visiting the Statue of Liberty in New York City. One of the children accidentally drops her backpack from the top of the viewing platform which is 300 feet above the ground. At what height will the kinetic energy of the backpack be equal to it's potential energy?
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In fact the actual height at which the two energies are equal can be determined only if there is a specified velocity. So by theoretically equating the energy equation we will arrive at the point that the height equal to 4.9 V².
What is kinetic energy?The kinetic energy of a body is the energy formed by virtue of its motion. It is directly proportional to the mass and velocity of the moving body and the equation is written as:
KE = 1/2 MV².
Potential energy is formed by virtue of the position of a body and it is equal to mgh. Where, g is gravitational acceleration equal to 9.8 m/s² and m is mass and h is the height from the ground.
The total of these two energy is called mechanical energy of a body and the total mechanical energy of a body is always conserved.
If the kinetic energy and potential energy are equal then the equations can be equated as:
1/2 mV² = mgh
V²/2 = gh.
=9.8 h
h = 4.9 V²
Therefore at a height of 4.9 V² the energies of the falling body will be equal where v is the velocity of the moving body.
To find more about mechanical energy, refer the link below:
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a force of magnitude 30 n stretches a spring 0.83 m from equilibrium. what is the value of the spring constant?
Answers
Answer:
36 N/m
Explanation: I got the answer right on the test ight noo cap
The neutrons in the nucleus of an atom have-
a. a positive charge
b. a negative charge
C. both positive & negative charges
d. no charge
Answers
Answer "d' no charge
Explanation:
They are as the name says neutral. They have no charge they are electrically neutral. Just as a proton is a positively charged particle and an electron carries a negative charge.
D. No charge
Black and splinter cleavage barely scratches glass
Answers
Answer:
oh I know that sounds good to me
What is the Speed of child falling from tree 5.0 meters high
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Lexington walked to her friends house.lexie walked 2miles west then 5 miles south then 3 miles east then 4 miles north then 2 miles east and finally 1 mile north what is levies distance and displacement.