Explanation:
Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.
The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.
However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.
1
A hockey player strikes a puck, giving it an initial velocity of 15.0 m/s in the positive x-direction. The puck slows uniformly to 6.20 m/s when it has traveled 45.0 m. (Take the direction of initial motion as the positive direction. Indicate the direction with the sign of your answer.) (a) What is the puck's acceleration? (b) At what velocity is it traveling after 2.80 s? (c) How long does it take to travel 45.0 m?
Answer:
a. -2.07 m/sc^2
b. 9.204
c. 4.25 seconds
Explanation:
a. The computation of puck's acceleration is shown below:-
[tex]V^2-Vo^2 = 2as\\\\ (6.20)^2 - (15)^2 = 2 a 45.0\\\\[/tex]
38.44 - 225 = 90a
= -2.07 m/sc^2
b. The computation of velocity is shown below:-
[tex]v = Vo + at[/tex]
= 15 - (2.07) × 2.80
= 9.204
c. The computation of long which take to travel is shown below:-
= (v - u) ÷ a
= (6.2 - 15) ÷ (-2.07)
= 4.25 seconds
We simply applied the above formulas so that the correct answers could be come
will a parachute work in a vacuum? yes or no and why or why not?
Answer:
No, they require air to operate.
Explanation:
:>
No
Explanation:
Because the parachute will not fit in the vacuum to trust me that's the answer
What is the charge of an atom with 21 protons and 6 electrons
Answer:
Scandium with an ion charge of +3
Explanation:
Answer:
i think it's 15
Explanation:
because the charge of a proton is +1 and for an electron it's -1
Lily replicates an experiment that found that the number of calories in a particular food is 50 kcal. She obtained data from five trials: 50 kcal, 72 kcal, 50 kcal, 12 kcal, and 50 kcal.
Which best describes her data results?
accurate
incorrect
invalid
precise
Answer:
b
Explanation:
The plate near the Artic Ridge is among those with the slower growth rates, moving slightly less than 2.5 cm/year. How much will the plate move in 10 years?
Answer:
B
Explanation:
A spacecraft is fueled using hydrazine (N2H4; molecular weight of 32 grams per mole [g/mol]) and carries 1640 kilograms [kg] of fuel. On a mission to orbit a planet, the fuel will first be warmed from −186 degrees Fahrenheit [°F] to 78 degrees Fahrenheit [°F] before being used after the long space flight to reach the planet. The specific heat capacity of hydrazine is 0.099 kilojoules per mole kelvin [kJ/(mol K)]. If there is 300 watts [W] of power available to heat the fuel, how long will the heating process take in units of hours [h]?
Answer:
The value is [tex]t = 689.029 \ hours [/tex]
Explanation:
From the question we are told that
The molar mass of hydrazine is [tex]Z = 32 g/mol = \frac{32}{1000} = 0.032 \ kg/mol[/tex]
The initial temperature is [tex]T_i = -186 ^o F = (-186-32) *\frac{5}{9} +273.15 = 152\ K[/tex]
The final temperature is [tex]T_f = 78 ^o F = (78-32) *\frac{5}{9} +273.15 = 298.7 \ K[/tex]
The specific heat capacity is [tex]c_h = 0.099 [kJ/(mol K)] = 0.099 *10^3 J/(mol/K)[/tex]
The power available is [tex]P = 300 \ W[/tex]
The mass of the fuel is [tex]m = 1640 \ kg[/tex]
Generally the number of moles of hydrazine present is
[tex]n = \frac{m}{Z}[/tex]
=> [tex]n = \frac{1640}{= 0.032}[/tex]
=> [tex]n = 51250 \ mol[/tex]
Generally the quantity of heat energy needed is mathematically represented as
[tex]Q = n * c_h * (T_f -T_i)[/tex]
=> [tex]Q = 51250 * 0.099 *10^3 * (298.7 - 152)[/tex]
=> [tex]Q = 7.441516913 * 10^{8} \ J[/tex]
Generally the time taken is mathematically represented as
[tex]t = \frac{Q}{P}[/tex]
=> [tex]t = \frac{7.441516913 * 10^{8} }{300}[/tex]
=> t = 2480505.6377 s
Converting to hours
[tex]t = \frac{2480505.6377}{3600}[/tex]
=> [tex]t = 689.029 \ hours [/tex]
The expression for thermal energy and power we were able to find the time necessary to heat the fuel is t = 689 h
To find
TimeThe international measurement system (SI) establishes the fundamental units in the measurement processes, this is defined by convention, giving uniformity in the calculation process and measurement exchange. Before starting the exercise we must reduce the magnitude to the SI system
PM = 32 g / mol ([tex]\frac{1 kg}{1000 g}[/tex] g) = 32 10-3 kg / mol
T₀ = 5/9 (ºF -32) + 273.15 = 5/9 (186 32) +273.15 = 152.0 K
T_f = 5 * (78 - 32) +273.15 = 298.7 K
c_e = 0.099 kj / mol k ([tex]\frac{1000J}{1 kJ}[/tex]) = 0.099 10³ J / mol K
The mole is the amount of matter of the international system (SI), the moles exist must be calculated since they are the mass of the compound for this we use a direct rule of proportions, if a mole has more than 32 10⁻³ kg, when moles are 1640 kg
n = [tex]\frac{m}{PM}[/tex]
n = 1640/32 10⁻³
n = 51.25 10³ mol
If we assume that all energy transfer is thermal, we can use
Q = [tex]m\ c_e ( T_f - T_o)[/tex]
Q = 51.25 10³ 0.099 10³ (298.7 -152.0)
Q = 7.44 10⁸ J
Power defined by the relationship between work and time
P = [tex]\frac{W}{t}[/tex]
In this case the thermal work is equal to the heat ( W=Q)
t = [tex]\frac{Q}{P}[/tex]
t = 7.44 10⁸ / 300
t = 2.48 10⁶ s
They indicate that the answer is given in hours, let's reduce the time
t = 2.48 106 s (1h / 3600s)
t = 6.89 10² h
In conclusion, with the relationship of thermal energy and power, we were able to set the time necessary for the amount of fuel to be t = 689 h
Learn more about thermal energy and power here:
https://brainly.com/question/11278589
Question 2 (1 point)
A tennis ball rolls off the edge of a table. the table is 0.55m tall and the tennis ball
lands 0.12m away from the table.
3
What is the initial vertical velocity?
0 m/s2
9
.12m
O m/s
-9.8m/s2
h
Question 3 (1 point)
Answer:
The initial vertical velocity is zero, u = 0 m/s
Explanation:
Given;
height of the table, h = 0.55 m
horizontal distance traveled by the tennis, x = 0.12 m
Apply the following kinematic equation;
h = ut + ¹/₂gt²
where;
u is the initial vertical velocity = 0, since the tennis ball rolled off the edge of a table.
h = ¹/₂gt²
The time to fall from the vertical height is given by;
[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2(0.55)}{9.8} }\\\\t = 0.335 \ s[/tex]
The initial horizontal velocity of the tennis is given by;
x = vₓt
vₓ = x / t
vₓ = (0.12) / (0.335)
vₓ = 0.358 m/s
Therefore, the initial vertical velocity is zero, u = 0 m/s and initial horizontal velocity, vₓ is 0.358 m/s
How can liquid pressure phenomena be used in daily life. Give one example with explanation of working?
Answer:
An example in which liquid pressure phenomena can be used in daily life is in Water blasting
Explanation:
Water blasting refers application of pressurized water to remove materials from the surface of objects.
There are different varieties of water blasting, including;
Hydrocleaning; Cleaning enabled by the use of high pressure water
Hydrodemolition; Demolition or removal of concrete using pressurized water
Hydrojetting; The spraying of water under pressure on surfaces in order to remove surface contaminants.
what forces are acting upon a coasting car
Answer:
f grav and f norm
Explanation:
A student hangs a weight on a Newton meter
Answer:
the energy currently stored in the spring in the newton meter is 0.045N. the student then increases the weight in the newton meter by 2N
What is the inverse square law and how does it relate to gravity?
Answer:
Inverse Square Law Newton proposed the Inverse Square Law. The effect of gravity (and also on forces such as sunlight) works like this. If say we have a half-mass Earth, it would produce a gravity of not half but a quarter (the square of 2).
Which bullet will hit the ground first ?
Answer:
they hit at the same time
Explanation:
Gravity works on both bullets the same.
All of the following are reasons that psychologists use a systematic method to conduct research except __________.
Answer: To help eliminate subjectivity
Explanation:
Edgenuity 2020
As shown in the figure below, a squirrel is looking for nuts. it runs rightward 10m and runs leftwards another 20m to a second nut. The total time spent running was 12s. What is the squirrels average velocity to reach the second nut?
Answer:
Average velocity = 0.83 m/s
Explanation:
Computation:
Total displacement = 20 - 10 = 10 m
Time taken = 12 second
Average velocity = Total displacement / Time taken
Average velocity = 10 /12
Average velocity = 0.83 m/s
Answer:
Velocity: -0.83
Average speed: 2.5
How do the earths layers compare to other planets in the solar system?
Answer:
Earth is made mostly of silicate rock in its crust and mantle, iron-nickel metal in the core. This is like some other planets -- but very unlike others.
An electric kettle is rated at 2 kW when connected to a 230 V electrical supply
a Calculate the current when the kettle is turned on.
b What value fuse should be included in the circuit of the kettle?
(Assume that the fuses available are 3 A, 5A and 13 A.)
c Modern kettles often have double insulation. Explain what this means
and how it provides extra safety for the user.
d ) Calculate the resistance of the heating element of the kettle.
Explanation:
a) P = IV
2000 W = I (230 V)
I = 8.7 A
b) The fuse must be rated for a higher current than the kettle, so use the 13A fuse.
c) Double insulation means there are two layers of insulation, insuring that the wires cannot touch the outer casing of the kettle and protecting the user from electrical shock.
d) V = IR
230 V = (8.7 A) R
R = 26.5 Ω
A beaker (glass jar) contains 1 kg of water; when converted to a volume measurement it is the same as:
1,000 mL
1,000 L
1,000 cm 3
Pick more than 1
Answer:
a and c
Explanation:
didn't actually do the math, but i am pretty positive that those are equal
What do (3.9 x 10^2)(4.1 x 10^4) equal
Answer:
Explanation:(3.9x100)(4.1x10,000)
390x41,000
15,990,000
What would you expect to happen to the acceleration if all friction were removed from the ramp, making the net force even higher than 600 N?
Answer:
if the friction was removed from the ramp, the acceleration would drasticly increase, making it hard to stop.
Explanation:
12 A plane starting from rest accelerates at 3 m/s for 25 s. Calculate the
increase in velocity after:
a 1 s
b 5s
C 25 s.
Answer: 78m/s =A
u=0 ,a=3m/sec^2 ,t=25sec
v=u+at
=0+25×3
=75m/s
after 1sec
v=u+at+75
=0+3×1+75
=78m/s
Explanation:
u=0 ,a=3m/sec^2 ,t=25sec
v=u+at
=0+25×3
=75m/s
after 1sec
v=u+at+75
=0+3×1+75
=78m/s
Based on their chemical formulas, which of these common substances is an
element?
A. Gold (Au)
B. Sugar (C6H1206)
C. Water (H20)
O D. Salt (NaCl)
Answer: C water
Explanation: The explanati is not hard cause the main elements of earth is fire ice water earth
Answer:
A. Gold (Au)
Explanation:
when a object is at rest, what is it’s speed??
Answer:
0 (there is no speed)
Explanation:
If an object is at rest, it is not moving, and it doesn't have a speed, so the speed is zero.
Answer:
the speed when object at rest is 0 m/s
George ran 50 meters to the right and then
turned around and ran 50 meters back to the
left. What is his total displacement?
a
100 meters left
b
50 meters left
С
50 meters right
d
O meters
Answer: d, o meters
Explanation:
Which event causes tides
Answer:
High tides and low tides are caused by the Moon.
Explanation:
The Moon's gravitational pull generates something called the tidal force.
Answer:
The moon is one
Explanation:
The moon has a strong gravitational force, and because of that it has certain control on Earth's oceans which can make tides
a car of mass 1200kg travelling at 30m/s runs into the back of a stationary
lorry. The car and lorry move at 4m/s after impact. Determine the mass of the
lorry.
Answer:
The mass of the lorry 7800 kg
Explanation:
Momentum conservation law for inelastic collision:
[tex]m1*V1 + m2*V2 =( m1 + m2)*V^{'} \\ \\1200*10^{3} g * 30 m/s + m2*0 m/s =(1200*10^{3} g + m2)*4 m/s\\ \\\frac{1200*10^{3} g * 30 m/s}{4 m/s} -1200*10^{3} g=m2\\ \\m2=9000*10^{3} g-1200*10^{3} g=7800*10^{3} g=7800 kg[/tex]
The process of predicting values that extend beyond the range of data points is called (5 points)
a
absolute value
b
extrapolation
c
interpolation
d
prediction
Answer:
The answer is B extrapolation
The process of predicting values that extend beyond the range of data points is called extrapolation, so option B is correct.
What is extrapolation?Extrapolation is a method of estimating a variable's value outside the original observation range using the relationship between the variable and another variable.
Extrapolation is comparable to interpolation in that it yields estimates between known observations, but extrapolation is more imprecise and more likely to yield meaningless findings. If identical approaches are assumed to be applicable, extrapolation may also refer to the extension of a method.
Creating a tangent line at the end of the known data and extending it past that point is known as linear extrapolation. Only when utilized to extend the graph of a roughly linear function or not too far beyond the existing data will linear extrapolation yield good results.
Therefore, the process of predicting values that extend beyond the range of data points is called extrapolation.
To know more about extrapolation:
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What is the main reason some people don’t stretch before exercising?
They don’t like to stretch.
They don’t need to stretch.
They are young.
They don’t know they should stretch.
Explanation:
They don’t like to stretch.
If Vector F represents the Fore of pushing a chair to North ,and its magnitude is 50 N ,What is the magnitude of the force after tripling it and pushed it to the south
150 N
- 100 N
300 N
-50 N
Explanation:
-100 n I think it so check this answer
a net horizontal force of 5000N is applied to a stalled car whose mass is 1500kg. what will be the car's speed after 10s?
Answer:
v=33.3ms⁻¹
Explanation:
F=ma
a=F/m
a=5000/1500
a=3.33ms⁻²
v=u+at
v=0+3.33×10
v=33.3ms⁻¹
PLEASE HURRY !!!!!!!!
An igneous rock has a coarse texture and is dark in color. How else can this rock be accurately described?
A. small crystals
B. cooled quickly
C. produced from magma
D. formed at Earth’s surface
igneous rocks are produced from magma
Answer:
Igneous rocks are produced from magma
Explanation:
I only answered so you could mark him brainliest
