Answer:
4.4 m
Explanation:
We are told the light from his flashlight, 1.3 m above the water level. Thus; h1 = 1.3m
Also,we are told that the light shone 2.5 m from his foot at the edge of the pool. Thus, L1 = 2.5 m
Angle of incidence θ1 is given by;
tan θ1 = L1/h1
tan θ1 = 2.5/1.3
tan θ1 = 1.9231
θ1 = tan^(-1) 1.9231
θ1 = 62.53°
Using Snell's law, we can find the angle of refraction from;
Sin θ2 = (η_air/η_water) Sin θ1
Where;
η_air is Refractive index of air = 1
η_water is Refractive index of water = 1.33
Thus;
Sin θ2 = (1/1.33) × sin 62.53°
Sin θ2 = 0.6671
θ2 = sin^(-1) 0.6671
θ2 = 41.84°
We want to find where the spot of light hit the bottom of the pool if the pool is 2.1 m deep. Thus, h2 = 2.1 m
Now, the spot can be found from;
L = L1 + L2
Where L2 = (h2) tan θ2
L = 2.5 + 2.1 tan 48.84
L = 2.5 + (2.1 × 0.8954)
L ≈ 4.4 m
Energy is transferred through a solid
by if there is a
between the ends of it.
Liquids and solids transfer energy
by because the particles can
Energy is transferred much
through an insulator
than it is through a conductor.
Tore
Answer:
Conduction is the transfer of thermal energy through direct contact between particles of a substance, without moving the particles to a new location. Usually occurs in solids. When heat is supplied to one end, molecules at that end start to move more quickly.
Explanation:
Conduction is the transfer of heat and electricity through a material or surface. Generally, metals are good conductors of heat and electricity.
What is Conduction?Conduction is the process through which heat energy is transmitted through the collisions which occur between neighboring atoms or molecules in a system. Conduction occurs more readily in the solids and liquid substances, where the particles are closer together than that of the gases, where the particles are further apart from each other.
Metals are good conductors of heat and electricity as they contain valence electrons and charge whereas non-metals are bad or poor conductors of heat and electricity as these elements does not contain valence electrons.
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A 1500-kg car travelling 90 km/h[N] collides with a 1200-kg minivan travelling 40 km/h[S]. After the collision, the two vehicles stick together.
a. Calculate the initial momentum of the car and the minivan.
b. Using the law of conservation of momentum, determine the total momentum of the two vehicles after the collision.
c. Calculate the final velocity of the two vehicles after the collision in metres per second.
Answer:
A) car - 37500 kg*m/s, minivan - 13332 kg*m/s
B) 50832 kg*m/s
C) 18.83 m/s
Explanation:
Realize that sticky collisions are modeled by: m1v1+m2v2=(m1+m2) vf
conevert to m/s....car going 25 m/s, minivan going 11.11 m/s
A) p=mv
p(car)=(1500)(25)
p(car)=37500 kg*m/s
p(minivan)=(1200)(11.11)
p(minivan)=13332 kg*m/s
B) 37500+13332=50832 kg*m/s
C) 37500+13332=(1500+1200) vf
50832=2700(vf)
18.83 m/s = vf
A positive charge Q2 is uniformly distributed over a nonconducting disc of radius a which has a concentric circular hole of radius b. At the center of the hole there is another nonconducting disc of radius d where a charge Q1 is uniformly distributed.
a) Find the surface charge density of the disc with the hole σ2.
b) Find the surface charge density 01 of the disc of radius d.
c) Find the total charge enclosed by the circle of radius
Answer:
a) σ = [tex]\frac{Q_1}{ a^2 - b^2}[/tex] , b) σ = [tex]\frac{Q_2}{d^2}[/tex] , c) Q_ {total} = Q₁ + Q₂, σ_ {net} = [tex]\frac{Q_1 + Q_2}{\pi \ a^2}[/tex]
Explanation:
a) The very useful concept of charge density is defined by
σ = Q / A
In this case we have a circular disk
The are of a circle is
A = π r²
in this case we have a hole in the center of radius r = b, so
A_net = π r² - π r_ {hollow} ²
A_ {net} = π (a² - b²)
whereby the density is
σ = [tex]\frac{Q_1}{ a^2 - b^2}[/tex]
b) The density of the other disk is
σ = Q₂ / A₂
σ = [tex]\frac{Q_2}{d^2}[/tex]
c) The total waxed load is requested by the larger circle
Q_ {total} = Q₁ + Q₂
the net charge density, in the whole system is
σ = [tex]\frac{Q_{total} }{ A_{total} }[/tex]
the area is
A_{total} = π a²
since the other circle is inside, we are ignoring the space between the two circles
σ_ {net} = [tex]\frac{Q_1 + Q_2}{\pi \ a^2}[/tex]
define static electricity and ohms law
Answer:
Static electricity : is a familiar electric phenomenon in which charged particles are transferred from one body to another
Ohm's law : states that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance
a
The
is a point that lies along a vertical line drawn from the suspension point of an object when the object is at
a standstill.
centripetal force
b. center of mass
c. equilibrium
d. center point
an inventor makes a clock using a brass rod and a heavy mass as a pendulum.WHAT Happens when the clock get colder?
An inventor makes a clock using a brass rod and a heavy mass as a pendulum. when the clock gets colder then the time clock would gain time
What is thermal expansion?The expansion of any material due to the variation of the temperature is known as thermal expansion. It varied differently for different materials according to their corresponding values of the coefficient of the thermal expansion.
As given in the problem statement that an inventor makes a clock using a brass rod and a heavy mass as a pendulum, when the clock gets colder then the length of the brass decreases due to thermal expansion.
The length of the pendulum gets reduced which further results in the reduction in the time period, as per the formula of the time period for the pendulum
T = 2π√(L/g)
As the length of the brass gets reduced. This means the pendulum of the clock moves faster and the clock would gain time
Thus, if a pendulum made of a heavy mass and a brass rod is used to create a clock by an inventor. The time clock would advance in time as the clock get colder
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[4] A tortoise and a hare cover the same distance in a race. The hare goes very fast but stops frequently while the tortoise has a steady pace and finish first
Answer:
I know that story where the hare sleeps
help me pls
An object accelerates if it:
a.) changes the direction of its velocity but not the magnitude
b.)changes the magnitude of the velocity but not the direction
c.)changes its speed
d.) all of the above
e.) none of the above
Answer:
D
Explanation:
Rhodium is in period 5 of the periodic table. What does this tell you about this element
(It’s number 4 in the picture)
Rhodium (Rh) is in period 5 on the periodic table. What does this tell you about this element ?
option - D
It has 5 energy levels/shells in its electron cloud.
With the information from the periodic table we can find that the correct statement is:
D. it is 5 energy level
The periodic table of the elements is a method of classifying the chemical elements based on their atomic number, it is divided into rows and columns
The rows are called the period and indicate the energy shell that is filled with electrons, all periods start with one electron and end when the shell is filled with 8 electrons.
The columns called groups correspond to elements that have the same number of electrons in their last shell, the chemical properties of the elements of the group are similar.
In this case we have an element the Rhodium, from period 5 and group VIIIB, when reviewing the period table it can be indicated that it has properties similar to cobalt and the inner layer is filled with two electors in its last layer.
When reviewing the different claims
a) False. The periodic table is not about molecules but about atoms
b) False. The metallic characteristics depend on the relationship between the number of electrons and the fermi level that is not indicated in the periodic table.
c) False. The number of protons is equal to the atomic number, in this case the rhodium has Z = 45, therefore it has 45 protons in the nucleus
d) True. It is at level 5 since the energy levels and the periods coincide.
In conclusion, with the information from the periodic table, we can find that the correct statement is:
D. it is 5 energy level
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A stream moving with a speed of 0.5 m/s reaches a point
where the cross-sectional area of the stream decreases to
one-fourth of the original area. What is the water speed in
this narrowed portion of the stream?
Explanation:
hi I like help but I couldn't
As an admirer of Thomas Young, you perform a double-slit experiment in his honor. You set your slits 1.03 mm apart and position your screen 3.19 m from the slits. Although Young had to struggle to achieve a monochromatic light beam of sufficient intensity, you simply turn on a laser with a wavelength of 641 nm . How far on the screen are the first bright fringe and the second dark fringe from the central bright fringe
Answer:
Δx = distance between central bright fringe and first bright fringe = 19.85 x 10⁻⁴ m = 1.985 mm
distance between central bright fringe and second dark fringe = 2.978 mm
Explanation:
We have the following data:
λ = wavelength of light = 641 nm = 6.41 x 10⁷ m
L = Distance of Screen from slits = 3.19 m
d = slit separation = 1.03 mm = 1.03 x 10⁻³ m
Δx = distance between consecutive bright fringes = fringe spacing = ?
Using formula:
[tex]\Delta x = \frac{\lambda L}{d}\\\\\Delta x = \frac{(6.41\ x\ 10^{-7}\ m)(3.19\ m)}{1.03\ x\ 10^{-3}\ m}[/tex]
Δx = distance between central bright fringe and first bright fringe = 19.85 x 10⁻⁴ m = 1.985 mm
distance between central bright fringe and second dark fringe = 1.5Δx
distance between central bright fringe and second dark fringe = (1.5)(1.985 mm)
distance between central bright fringe and second dark fringe = 2.978 mm
A snail traveled 3.12 meters in 27.13 minutes. What is the snails speed in meters per second
Answer:
0.002 m/s
Explanation:
27.13(60) = 1,627.8 seconds
3.12/1,627.8 = 0.00191 ≈ 0.002 = s
Are you sure you're not looking for cm/s?
(d) Suppose you use a spring to launch a payload horizontally from the asteroid so that the payload ends up far from the asteroid, travelling at a speed of 3 m/s. The payload has a mass of 29 kg. If the spring is to be compressed initially an amount of 1.4 m, what stiffness ks must the spring be designed to have
Answer:
ks= 133.2 N/m
Explanation:
Assuming that we can neglect the gravitational potential energy of the mass, and that no other forces acting on the payload, total mechanical energy must be conserved.This energy, at any time, is part elastic potential energy (stored in the spring) and part kinetic energy.When the spring is initially compressed, the payload is at rest, so all energy is elastic potential.Once the spring has returned to its natural state, all this elastic potential energy must have been turned into kinetic energy.If the payload is launched horizontally, and no gravity is present,this means that its final speed will be horizontal only also, according to Newton's First Law.So, we can write the following equation:[tex]\Delta U + \Delta K = 0 (1)[/tex]
where ΔU = -1/2*k*(Δx)² (2)and ΔK = 1/2*m*v² (3)Replacing in (2) and (3) by the givens, and simplifying, we can find the stiffness ks as follows:[tex]k_{s} =\frac{m*v^{2}}{\Delta x^{2}} = \frac{29 kg*(3m/s)^{2}}{(1.4m)^{2}} = 133.2 N/M (4)[/tex]
Define the term pressure
Answer:
Pressure is the perpendicular force applied per unit area.
what dose nuclear reactions produce?
Answer:
a new chromebook for you and you will get to know the other one that
Rhodium is in period 5 of the periodic table. What does this tell you about this element
Answer:
. It is an extraordinarily rare, silvery-white, hard, corrosion-resistant, and chemically inert transition metal. It is a noble metal and a member of the platinum group.
Explanation:
write 20 physical Quantities withS.I unit and formula
Answer:
HERE IS YOUR ANSWER
Physical quantity => Unit
1)Length=>metre
2)Time=>second
3)Temperature=>Kelvin
4)mass=>kilogram
5)electric current=>ampere
6)luminous intensity=>candela
7)amount of substance=>mole
8)velocity=>m/s
9)acceleration=>m/s²
10)momentum=>kgm/s
11)density=>kg/m³
12)volume=>m³
13)force=>Newton(N)
14)Energy=>Joule(J)
15)Power=>Watt(W)
16)Pressure=>Pascal(Pa) or N/m²
17)Resistance=>ohm
18)Electrical potential=>volt(V)
19)plane angle=>radian
20)solid angle=>steradian
Explanation:
Physical quantity:-units
Force, Weight:-NewtonFrequency:-Hertz.Electric charge:-CoulombElectric potential (Voltage):-Volt.Inductance:-Henry.Capacitance:-FaradResistance, Impedance, Reactance:-OhmElectricalconductance:-Siemens.Magneticflux:-WeberMagnetic flux density:-Tesla.Energy, Work, Hea:- JoulePower, Radiant flux:-WattAngle:- RadianRadioactivity :-BecquerelLuminous flux:-lemanA psychologist is interested in exploring the effect tutorial support on students academic performance and assign students in to two groups.students in group one get the tutorial support and those in group two do not.In this example what is dependent variable,independent variable,control groupand experimental group
The dependent variable is academic performance while the independent variable is presence/absence of tutorial support.
The correct results are:
The dependent variable is academic performanceThe independent variable is the presence/absence of tutorial supportThe control group are students who did not get the tutorial support.The experimental group were students that got the tutorial supportIn every experiment, there is a dependent and independent variable as well as an experimental and a control group.
The experimental group receive the treatment while the control group do not receive the treatment. The independent variable is manipulated and its impact on the dependent variable is evaluated.
The control group are students who did not receive the tutorial support while the experimental group are students that received the tutorial support.
The dependent variable in this case is academic performance. Its outcome depends on the presence or absence of tutorial support (independent variable).
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Which time interval has the greatest speed?
Answer:
es la 2
Explanation:
epero que te curva
Two 20kg spheres are placed with their
Centres 50cm apart. What is the magnitude of
gravitational force each exerts on the other?
Answer:
F = 1.07 x 10⁻⁷ N
Explanation:
The gravitational force of attraction between two objects can be found by the use of Newton's Gravitational Law:
[tex]F = \frac{Gm_{1}m_{2}}{r^2}\\\\[/tex]
where,
F = Gravitational Force of attraction = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
m₁ = m₂ = mass of spheres = 20 kg
r = distance between the objects = 50 cm = 0.5 m
Therefore,
[tex]F = \frac{(6.67\ x\ 10^{-11}\ N.m^2/kg^2)(20\ kg)(20\ kg)}{(0.5\ m)^2}\\\\[/tex]
F = 1.07 x 10⁻⁷ N
Highest density of electrostatic charges in a metal is found where
I don't know the answer but I just want points sorry
A car's initial speed of 15m/s is running with the acceleration of 32m/
s2 in 8 seconds. What is the car's final velocity?
Explanation:
15m/s
acceleration= (+)
so, 15m/s +32m/s=47m/s
42m/s. X 8 = 336
How does the REE change as a person ages?
Explain
I go to k12 too and i am writing this test now too. I am like pretty sure my answer is correct. I guess we can kinda help eachother with this assignment cuz i am sorta stuck too.
The older a person gets, the greater REE he has.I dont know i hope this helped a bit I know its not much i need help with this too.
If matter cannot be created or destroyed, then how do you end up with
rust? Below is the equation for rust.
4Fe + 302 → 2Fe203
oxygen from the air
water in the atmosphere
oxygen from in the metal
there shouldn't be any oxygen
Your question is a "non sequitur", which means "it doesn't follow".
Your "then" doesn't contradict your "If", so no mystery is implied.
Maybe you're trying to say that matter is somehow not conserved in the equation . . . 4Fe + 302 → 2Fe203 . But it is. There are 4 Irons and 6 Oxygens on each side, so conservation is not violated here.
I looked up "rust" on Floogle, and got slapped with pages and pages of chemistry that I don't completely understand. But what it's saying is that rusting is a very complex chemical process, AND it doesn't happen unless there's some water involved.
So the bottom line is that there's a lot more going on than simply
4Fe + 302 → 2Fe203 ,
there's water going in and out of the process at every stage, and when it's all over, you have rusty iron, and mass has been conserved.
Time of the day when the Sun does not shine (___time)
N____N
Magnetism is a type of
A. force
B. energy
C. gravity
D. electricity
Answer:
A. force
Explanation:
Magnetism is a type of force.
Answer:
A. force
Hope this helps
(a) What do you mean by rest?
A small dog is trained to jump straight up a distance of 1.1 m. How much kinetic energy does the 7.7 kg dog need to jump this high?
Answer:
83.09 J
Explanation:
The potential energy at the point of the top of the jump is represented by the equation
[tex]mgdeltah[/tex]
when the dog jumps, all the potential energy converts to kinetic energy (1/2mv^2). Plugging in the values:
(7.7)(4.184)(1.1) = 83.0907 J
PLEASE HELP WILL GIVE BRALIEST
12. A bird flies 10 m in 2 seconds. What is its speed?
13. A plane takes 8 hours to fly 5000 km. What is its speed?
14. When given a motion graph, how can you tell if it’s a speed graph or acceleration graph?
Answer:
12: If the bird flies 10m in 2s, it's speed is then 10m/2s, which we can simplify giving us 5m/s
13: Flying 5000 km in eight hours means that it's flying at (5000 / 8)km/h, or 625km/h
14: A speed graph will not go below zero, an acceleration graph will.
What is diffraction of light
Answer:
According to "http://ww2010.atmos.uiuc.edu" Diffraction is the slight bending of light as it passes around the edge of an object.
Some examples of Light Defraction would be..
-CD reflecting rainbow colours
-Sun appears red during sunset
-From the shadow of an object