Answer:
1.7 BTU
Explanation:
q = mCΔT
q = (25 g) (0.9 J/g/°C) (100°C − 20°C)
q = 1800 J
q = 1800 J × (1 BTU / 1055 J)
q = 1.7 BTU
the indiscriminate use of drugs without the doctor's prescription is called
Answer:
drug misuse
Explanation:
this is because the person is using those drugs but indiscriminately meaning without correct judgement or in this context without a prescription therefore without following guidelines and legal standards eg self medication
but it is not abuse because it is being used for its intended purpose just without any guidelines
anyone can solve these numerical please.
Explanation:
2. Sum the torques about the fulcrum.
(450 N) (2 m) − (350 N) x = 0
x = 2.57 m
3. Sum the torques about the fulcrum.
(3600 N) (0.20 m) − F (0.90 m) = 0
F = 800 N
Mechanical advantage is the ratio between the load force and effort force.
MA = 3600 N / 800 N
MA = 4.5
Velocity ratio is the mechanical advantage divided by efficiency. Assuming the lever is 100% efficient:
VR = 4.5 / 1
VR = 4.5
4. Mechanical advantage is the ratio between the load force and effort force.
MA = 900 N / 600 N
MA = 1.5
The velocity ratio is the distance moved by the effort divided by the distance moved by the load. For a 3 pulley system, VR = 3.
Efficiency is mechanical advantage divided by velocity ratio.
e = 1.5 / 3
e = 0.50
5. Sum the torques about the fulcrum.
(-300 N) (0.10 m) + F (0.03 m) = 0
F = 1000 N
Halley is standing outside on a cloudy day. When she hears thunder, she goes back inside so that she doesn't get caught in
a storm. Is this an example of inference or prediction? Explain
Answer:
Inference
Explanation:
An inference involves the application of logic to progress from a premise to a conclusion or logical consequence on the basis of the evidence or known fact. Inference is a process of thought that be divided into a deduction and an induction aspect.
In the given question Halley, by standing outside was able to deduce the sound of thunder she is then able by inductive reasoning from the fact that storms are usually preceded by and accompany lightening, conclude that there is a storm coming.
Calculate the Schwarzschild radius (in kilometers) for each of the following.1.) A 1 ×108MSun black hole in the center of a quasar. Express your answer using two significant figures.2.) A 6 MSun black hole that formed in the supernova of a massive star. Express your answer using two significant figures.3.) A mini-black hole with the mass of the Moon. Express your answer using two significant figures.4.) Estimate the Schwarzschild radius (in kilometers) for a mini-black hole formed when a superadvanced civilization decides to punish you (unfairly) by squeezing you until you become so small that you disappear inside your own event horizon. (Assume that your weight is 50 kg.) Express your answer using one significant figure.
Answer:
(I). The Schwarzschild radius is [tex]2.94\times10^{8}\ km[/tex]
(II). The Schwarzschild radius is 17.7 km.
(III). The Schwarzschild radius is [tex]1.1\times10^{-7}\ km[/tex]
(IV). The Schwarzschild radius is [tex]7.4\times10^{-29}\ km[/tex]
Explanation:
Given that,
Mass of black hole [tex]m= 1\times10^{8} M_{sun}[/tex]
(I). We need to calculate the Schwarzschild radius
Using formula of radius
[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]
Where, G = gravitational constant
M = mass
c = speed of light
Put the value into the formula
[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times1\times10^{8}\times1.989\times10^{30}}{(3\times10^{8})^2}[/tex]
[tex]R_{g}=2.94\times10^{8}\ km[/tex]
(II). Mass of block hole [tex]m= 6 M_{sun}[/tex]
We need to calculate the Schwarzschild radius
Using formula of radius
[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]
Put the value into the formula
[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times6\times1.989\times10^{30}}{(3\times10^{8})^2}[/tex]
[tex]R_{g}=17.7\ km[/tex]
(III). Mass of block hole m= mass of moon
We need to calculate the Schwarzschild radius
Using formula of radius
[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]
Put the value into the formula
[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times7.35\times10^{22}}{(3\times10^{8})^2}[/tex]
[tex]R_{g}=1.1\times10^{-7}\ km[/tex]
(IV). Mass = 50 kg
We need to calculate the Schwarzschild radius
Using formula of radius
[tex]R_{g}=\dfrac{2MG}{c^2}[/tex]
Put the value into the formula
[tex]R_{g}=\dfrac{2\times6.67\times10^{-11}\times50}{(3\times10^{8})^2}[/tex]
[tex]R_{g}=7.4\times10^{-29}\ km[/tex]
Hence, (I). The Schwarzschild radius is [tex]2.94\times10^{8}\ km[/tex]
(II). The Schwarzschild radius is 17.7 km.
(III). The Schwarzschild radius is [tex]1.1\times10^{-7}\ km[/tex]
(IV). The Schwarzschild radius is [tex]7.4\times10^{-29}\ km[/tex]
The energy conservation allows to find the Schwarschild radius for several bodies of different masses are:
1) Black hole quasar is: r = 2.9 10⁸ km
2) Blsck hole supernove is: r = 17.7 km
3) Mini black hole is: r = 1.1 10⁻⁷ km
4) Human body is: r= 7 10⁻²⁹ km
The schwarschild radius is defined as the distance from a black hole center at radius which the escape velocity is equal to the light speed, in some cases it is also called the event horizon.
Let's use Newton's second law where force is the universal law of attraction and acceleration is centripetal.
F = ma
F = [tex]G \frac{Mm}{r^2}[/tex]
Where F is the force, M the mass of the black hole, m the handle of the body, r the radius and v the speed of the body.
The energy of the gravitational field is
F = [tex]- \frac{dU}{dr }[/tex]
U = [tex]-G \frac{Mm}{r}[/tex]
Let's use conservation of energy
Em₀ = K + U = ½ m v² - [tex]G \frac{Mm}{r}[/tex]
In infinity the energy
Em_f = 0
energy is conserved
Em₀ = Em_f
½ m v² - [tex]G \frac{Mm }{r}[/tex] = 0
r = [tex]\frac{2GM}{v^2}[/tex]
From the definition of the Schwarschild radius this speed is equal to the light speed
v = c
r = [tex]\frac{2GM}{c^2 }[/tex]
They ask to calculate the radius for several cases of different mass, claculate the constant value
V = [tex]\frac{2 \ 6.67 \ 10^{-11} }{(3 \ 10^8) ^2 }[/tex]
V = 1.482 10⁻²⁷
1) A black hole of mass M = 1 10⁸ [tex]M_{sum}[/tex]
The tabulated mass of the sun is [tex]M_{sum}[/tex] = 1.989 10³⁰ kg
Let's substitute
r = 1.482 10⁻²⁷ 1 10⁸ 1.989 10³⁰
r = 2.94 10⁸ km
With two significant figures
r = 2.9 10⁸ km
2) A black hole of mass M = 6 [tex]M_{sum}[/tex]
r = 1.482 10⁻²⁷ 6 1.989 10-30
r = 17.7 km
3) a mini black hole with the mass of the moon
Tabulated mass of the moon M = 7.35 10²² kg
r = 1.482 10⁻²⁷ 7.35 10²²
r = 1.1 10⁻⁷ km
4) A person of M = 50 kg
r = 1.482 10⁻²⁷ 50
r= 7 10-29 km
In conclusion using the conservation of energy we can find the Schwarschild radius for several bodies of different masses are:
1) Black hole quasar is: r = 2.9 10⁸ km
2) Blsck hole supernove is: r = 17.7 km
3) Mini black hole is: r = 1.1 10⁻⁷ km
4) Human body is: r= 7 10⁻²⁹ km
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What is CGS unit of weight
Answer:
[tex] \boxed{dyne}[/tex]Explanation:
The weight of a body is defined as the force with which it is attracted towards the centre of a planet. A spring balance measures it. It's unit is Newton ( N ) in the SI system and dyne in the CGS system.
Hope I helped!
Best regards!
Weight is force.
The CGS unit of force is the dyne.
The SI unit of force is the Newton.
1. The first stage of stellar formation is the assembly (or formation) of a_______ . 2. Stars form in clouds. 3. When a cloud collapses it into smaller and smaller pieces till those pieces reach stellar masses. 4. As the density increases, the fragments become_______ , which________ the temperature of the cloud and inhibits further fragmentation. 5. The _______then condense into rotating globs of gas that serve as stellar embryos. 6. During this stage the surface temperature_______ and luminosity_________ despite decreasing size. 7. The central temperature and pressure increase as the potential energy is converted to energy due to contraction.
Answer: The keywords to input into the blank spaces were omitted which are ; fragments, increases, decreases, opaque, raises, molecular, protostar, gravitational, thermal.
Please find the answers for the blank spaces in the explanation column
Explanation:
1. The first stage of stellar formation is the assembly (or formation) of a_PROTOSTAR______ . 2. Stars form in MOLECULAR clouds. 3. When a cloud collapses, it FRAGMENTS into smaller and smaller pieces till those pieces reach stellar masses. 4. As the density increases, the fragments become_OPAQUE______ , which___RAISES_____ the temperature of the cloud and inhibits further fragmentation. 5. The __FRAGMENTS_____then condense into rotating globs of gas that serve as stellar embryos. 6. During this stage the surface temperature INCREASES_______ and luminosity__INCREASES_______ despite decreasing size. 7. The central temperature and pressure increase as the GRAVITATIONAL potential energy is converted to energy due to THERMAL contraction.
The above describes the evolution or formation of stars which begins with the collapse of a molecular cloud by gravitational force, this collapse cause the molecular cloud to fragment with the release of heat --Gravitation potential energy causing an increased temperature and pressure of the newly condensing fragment with increasing luminosity known as a Protostar.
what is the frequency and wavelength of a remote control? PLEASE HURRY
Answer:
940 nanometers wavelength, and about an 300 mHz - 400 gHz frequency
The ways to measure the mass and volume of irregular object
Answer:
When we have irregular objects, it may become very hard to calculate the volume of the object, as we actually can not use any simple equation to find it.
The mass is less tricky, just find a scale and wheight it, now we know the mass of the irregular object.
One way to measure the volume of the object is using water... how we do it?
Get some recipient with water, measure the height of the water.
Introduce your object into the water and totally submerge it, now the level of the water will rise. This is because as you introduce the object under the water, you are displacing up a given volume of water that has the same volume as the irregular object.
Now that you know the height of the water before and after you put your object, you can easily calculate the volume of water displaced, and that will be the volume of the object (the tricky part may be totally submerging the object if, for example, is wood and it floats, here you can use a thin wire to push it down but it will affect a little bit the measures.)
placement.
A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens
to its kinetic energy when its reaches the maximum height? Why?
If the speed of a body is increased four times, how will its kinetic energy be affected?
Answer:
kinetic energy will be equal to 0
Explanation:
this is because at final position velocity of body will become zero.
kinetic energy eill be 8 times
as fast as you can find the answer
Answer:
Explanation:
a) From the diagram, the load will be expressed in newton. The load will be the weight of the box on the inclined plane.
Load = mass * acceleration due to gravity.
Given the mass of the object = 100kg
acceleration due to gravity = 9.8m/s²
Load (in Newton) = 100*9.8
Load (in Newton) = 980N
b) The formula for calculating the velocity ratio of an inclined plane is expressed as VR = 1/sinθ where θ is the angle of inclination.
Given θ = 30°,
VR = 1/sin30°
VR = 1/0.5
VR = 1/(1/2)
VR = 1* 2/1
VR = 2
The velocity ratio is 2.
c) Length of the inclined plane can be calculated using the SOH, CAH, TOA trigonometry identity.
According to SOH, sinθ = opposite/hypotenuse
sin30° = 1/2 = opp/hyp
This shows that the opposite side of the triangle is 1 and the hypotenuse is 2. The length if the inclined is the length of the longest side i.e the hypotenuse. Hence the length of the inclined plane is 2m
d) Mechanical Advantage is the ratio of the load to the effort applied on an object.
Given the Load = 980N and the effort applied to the load on the incline plane = 400N
MA = Load/Effort
MA = 980/400
MA = 2.45
e) Efficiency = MA/VR * 100
Efficiency = 2.45/2 * 100
Efficiency = 122.5%
You are hiking in a canyon and you notice an echo. You decide to let out a yell and notice it took 2 seconds before you heard the echo of your yell. How far away is the canyon wall that reflected your yell
Answer:
d = 343 m
Explanation:
Given that,
You notice that an echo took 2 seconds before you heard the echo of your yell.
We need to find that how far away is the canyon wall that reflected your yell. It means we need to find the distance.
The distance covered by an object is given by :
d = v × t
v is speed of sound in air, v = 343 m/s
The sound took 1 s to reach the wall and 1 s back to you.
It means that,
d = 343 × 1
d = 343 m
So, canyon will reflect your yell at a distance of 343 m
What is the equation for burning a fossil fuel
Answer:
Fuel + O2 → CO2 + H2O
Explanation:
A capacitor C is fully charged by connecting it to battery of V Volt. Then it is disconnected from battery. If the separation between the plates is halved, what will happen to (i) Charged stored by capacitor (ii) Potential difference across it. (iii) Electric filed strength between the plates. (iv) Energy stored by the capacitor.
Answer:
Explanation:
i )
When it is disconnected with the battery , the charge stored in it becomes fixed . When the plate distance becomes half , its capacitance becomes twice from C to 2C . Let charge stored in it at the time of disconnection from battery be Q . Let plate separation reduces from d to d / 2
So charged stored in it will remain unchanged .
ii )
Potential difference = charge / capacitance
in the first case potential difference = Q / C
in the second case potential difference = Q / 2C
So potential difference becomes half .
iii ) electric field = potential diff / plate separation
in the first case electric field = Q / (d x C )
in the second case electric field = 2 Q / (d x 2C)
= Q / (d x C )
So electric field remains unchanged .
iv)
energy stored in first case = Q² / 2C
In the second case energy stored = Q² / 2x2C
so energy stored becomes half .
A ship sets out to sail to a point 123 km due north. An unexpected storm blows the ship to a point 112 km due east of its starting point. (a) How far and (b) in what direction (as an angle from due east, where north of east is a positive angle) must it now sail to reach its original destination
Answer:
Explanation:
We shall represent the point of destination and point of new starting point in vector form .
i and j will represent east and north .
point of destination = 123 j
starting point = 112 i
distance between the two
D = 123 j - 112 i
magnitude of D = √ ( 123² + 112² )
= 166.35 km
Direction of D
Tanθ = - 123 / 112
= - 1.09
θ = 132.54 degree from east in positive angle .
give an example of a balanced force and explain what makes it a balanced force
What would happen to the
to the output force (F2)if the area
of the piston1 is made larger than that of piston2? plz help
Answer:
The output force would decrease since exerted force is inversely proportional to contact area.
Explanation:
F ∝ [tex]\frac{1}{A}[/tex] , Where 'F' is the exerted force and 'A' is the contact area.
Determine whether each sum, difference, product,
or quotient represents a rational number or an
irrational number. Explain how you know without
simplifying
Explanation:
The asked in the Question is missing, although i am assuming the number
as [tex]\frac{6}{23}[/tex] ÷[tex]\frac{\sqrt{2} }{2}[/tex].
The given expression contains an irrational number. So, the quotient will also be an irrational number.
Solving
[tex]\frac{6}{23}\times\frac{\sqrt{2} }{2} \\=\frac{3\sqrt{2} }{23}[/tex]
Which is an irrational number.
The rhinestones in costume jewelry are glass with index of refraction 1.50. To make them more reflective, they are often coated with a layer of silicon monoxide of index of refraction 2.00. What is the minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference?
Answer:
60
Explanation:
According to the given question, the computation of minimum coating thickness is shown below:-
The condition for constructive interference is
[tex]2t_{min} = (m + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]= (0 + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]t = \frac{\lambda}{4n}[/tex]
Now we will put the values to the above formula to reach the answer
[tex]= \frac{480nm}{4\times 2.0}[/tex]
= 60
Therefore we simply applied the above formula to determine the minimum coating thickness
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
Given that, the index of refraction of glass is 1.50 and the index of refraction of silicon monoxide is 2.00. The wavelength light of 480 nm.
If [tex]\lambda {c}[/tex] is the wavelength in the coating and λ is the wavelength in vacuum, then [tex]\lambda_{c} = \dfrac {\lambda}{n}[/tex] where n is the index of refraction of the coating.
Thus, the minimum coating thickness [tex]T_{min}[/tex] can be calculated as,
[tex]2T_{min} = (m+\dfrac {1}{2})\times\dfrac {\lambda} {n}\\\\T_{min} = (m+\dfrac {1}{2}) \times\dfrac {\lambda} {2n}[/tex].
For the constructive interference, m = 0.
So [tex]T_{min} = \dfrac {\lambda} {4n}[/tex]
[tex]T_{min} = \dfrac {480\rm nm} {4\times2.0}[/tex]
[tex]T_{min} = 60[/tex]
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
For more details, follow the link given below.
https://brainly.com/question/15541641.
For each of the following statements about deep-water waves, determine if the statement is true or false, then explain why: The longer the wave, the deeper the wave base. The greater the wave height, the deeper the wave base. The longer the wave, the faster the wave travels. The greater the wave height, the faster the wave travels. The faster the wave, the greater the wave height.
Answer:
The longer the wave, the deeper the wave base - True
The greater the wave height, the deeper the wave base - false
The longer the wave, the faster the wave travels- true
The greater the wave height, the faster the wave travels- false
The faster the wave, the greater the wave height - False
Explanation:
When a wave has a high length it means that the wave base will be deeper.
The longer the wave, the deeper the wave base - True
When the weight height is big , the wave base will be deeper.
The greater the wave height, the deeper the wave base - false
The longer the wave, the faster the wave travels- true
The greater the wave height, the faster the wave travels- false
The faster the wave, the greater the wave height - False
A space rocket accelerates uniformly from rest to 160ms^-1 upwards in 4.0s, then travels with a constant speed of 160ms^-1 for the next 5.0s.
What is the initial acceleration of the rocket?
Answer:
40 ms¯².
Explanation:
To solve this problem, we shall illustrate the question with a diagram.
The attached photo gives a better understanding of the question.
From the attached photo:
Velocity (v) = 160 ms¯¹
Time (t) = 4 secs.
Acceleration (a) =?
Acceleration (a) = Velocity (v) /time (t)
a = v/t
a = 160/4
a = 40 ms¯²
Therefore, the initial acceleration of the rocket is 40 ms¯².
what is the function of eye lens of the human eye
Answer:
Lens of the human Eye is a important and one of that most complex sense organ.
Explanation:
Lens of the human eye it helps that in visualizing light and color perception and objects , glance on the human eye structure and function.
Sense organs are much pretty similar to the camera they help us see the objects clear.
A human eye is the 2.3 cm in diameter and all filled some fluid, and there are following parts in eye:- cornea, Retina , Lens ,Pupil , optic nerves.
cornea :- the cornea is the first transparent part of is called cornea, enters the light through the cornea.
Retina :-it is light sensitive layer that consists of nerve cells,then transmitted to the brain through nerves.
Lens:- behind the pupil there is a transparent structure called lens,it shape focus light on the retina.
Pupil:-it control the value of light that enters the human eye.
Optic nerves is are the two types :- (1) cones (2) Rods .
Answer:
It causes Light Rays to converge on the retina
Explanation:
I took the K12 Test
Astronomers can now report that active star formation was going on at a time when the universe was only 20% as old as it is today. When astronomers make such a statement, how can they know what was happening inside galaxies way back then
Answer:
First, as you may know, the light travels at a given velocity.
In vaccum, this velocity is c = 3x10^8 m/s.
And we know that:
distance = velocity*time
Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.
This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)
Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.
The astronomers could know what was happening inside galaxies way back then by the fact that;
they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find
Astronomers Measure the wavelength of the light that is stretched, so the light is seen as 'shifted' towards the red part of the spectrum by using spectroscopy. This measure is also called redshift.
This invokes a ray of light through a triangular prism that splits the light into various components known as spectrum.
The way the astronomers could use this concept to know what was happening in the galaxies before is by examining the spectra of galaxies that have the highest redshifts.
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If you told a policeman about a car traveling 44.704 m/s (100 mph) that was traveling in an eastward direction, you would be describing the car's ___.
Answer:
Velocity
Explanation:
You would be describing the velocity of the car.
Velocity in physics is defined as Vector quantity that describes the displacement of an object with respect to the time it takes to attain it. Displacement is the addition of direction to the speed of an object. The displacement is noted in the question, "traveling eastward". While it is stated that the car travels at 44.704 m/s. Ordinarily, it would have been tagged speed, if not for the direction added to it which makes it velocity.
I hope you understand.
2. Adelia holds a shiny steel spoon with its back (convex surface) facing her eyes at a distance
of approximately 30 cm. She sees an upright image of herself. However, when the spoon
is changed so that the front (concave surface) of the spoon is facing her eyes, an inverted
image is observed.
(a) Explain this situation.
(b) Why is an upright image not seen on the front surface of the spoon at that distance?
Answer:
(a) The convex mirror image, is always upright at all positions, while images formed by concave mirrors are always inverted when the object distance from the mirror is more than the mirrors focal length.
(b) An upright image is not seen for object at a distance from a concave mirror further than the focal length of the mirror, which is the spoon in the question
Therefore, the location of her eyes of approximately, 30 cm, from the mirror is more than the mirror's focal length
Explanation:
Air contains 78.08% nitrogen, 20.095% oxygen, and 0.93% argon. a sample of air occupies 8 l at 273 k and applies a pressure of 2.45 atm to its container. the sample of air is heated to 550 k, at which time it takes up 11.8 l. what is the partial pressure of nitrogen after the air has been heated
Answer:
the partial pressure of nitrogen after the air has been heated is 2.61atm
Explanation:
Using combined gas law which is the combination of Boyle's Law and Charles' Law, and it gives The relationship between pressure, volume, and absolute temperature
PV/T= K
P1₁V₁/T₁=P₂V2₂/T₂
P₂=final pressure= ?
P₁= initial pressure=2.45 atm
.T₁= initial temperature= 273k
T₂= final temperature= 550 K,
We can make P₂ subject of the formula then we have
P₂=P₁V₁T₂/T₁T₂
=( 2.45×8×550)/(273×11.8)
P2=3.35atm
Now we can calculate the partial pressure of N₂
N₂= 3.35×(78.08/10)
=2.61atm
Therefore, the partial pressure of nitrogen after the air has been heated is 2.61atm
ball is thrown upward from a window that is 12 m above the ground. The ball reaches a maximum height of 4 m above the window before falling all the way down to the ground. What distance did the ball travel?
Answer:
20 m
Explanation:
The ball travels 4 m up, then 16 m down. It travels a total distance of 20 m.
Which statement describes one feature of Rutherford's model of the atom?
O The atom is mostly empty space.
O The atom cannot be divided into smaller particles.
O Electron clouds are regions where electrons are likely to be found.
O The electrons are located within the positive material of the nucleus.
Answer:
The atom is mostly empty space.
Explanation:
Ernest Rutherford in the year 1911 developed a model of an atom. In his model the atom was shown that the atom is mostly empty spaces composed of negative electrons which orbits round a positive nucleus just like planets revolving round the sun.
Rutherford came up with this model by performing experiments in 1909 which involves the scattering of alpha particles on a thin gold foil. From this experiments he came up with his model.
Answer:
A!
Explanation:
The atom is mostly empty space.
A concave mirror has a radius of curvature of 80cm. If the real image of an object is formed at 1m, how far from the mirror is the object?
Answer:
66.7 cm
Explanation:
The focal length is half the radius of curvature, or f = 40 cm.
The image is real, so i = +100 cm.
The distance to the object is therefore:
1/o + 1/f = 1/i
1/o + 1/40 = 1/100
o = -66.7 cm
The object is 66.7 cm left of the mirror.
A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is:
Answer:
[tex]\lambda[/tex] = 40 cm
Explanation:
given data
string length = 30 cm
solution
we take here equation of length that is
L = [tex]n \times \frac{1}{4} \lambda[/tex] ...............1
so
total length will be here
[tex]L = \frac{\lambda}{2} + \frac{\lambda}{4}\\[/tex]
[tex]L = \frac{3 \lambda }{4}[/tex]
so [tex]\lambda[/tex] will be
[tex]\lambda = \frac{4L}{3}\\\lambda = \frac{4\times 30}{3}[/tex]
[tex]\lambda[/tex] = 40 cm
A car is traveling to the right with a speed of 2.0\,\dfrac{\text m}{\text s}2.0 s m 2, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction on an icy road when the brakes are applied. The car slows down with constant acceleration for 3.0\,\text m3.0m3, point, 0, start text, m, end text until it comes to a stop. How long does it take the car to slide to a stop?
Answer:
It took the car 3 second to come to full stop
Explanation:
When the car is driving to the right at a speed of 2 m/s, and suddenly brakes giving the car a constant negative acceleration making it travel 3 meters after it stops, we can use the following kinematic equation to solve for the acceleration applied by the brakes:
[tex]v=v_0-a\,t\\0=2-a\,t\\a=\frac{2}{t}[/tex]
and we use this result in the following kinematic equation for the distance traveled to find the time it took it to stop:
[tex]x-x_0=v_0\,t-\frac{1}{2} a\,\,t^2\\3=2\,t -\frac{1}{2} (\frac{2}{t}) \,\,t^2\\3=2\,t-t\\3=t[/tex]
therefore, it took the car 3 seconds to come to a full stop.
