Answer:
The critical radius of the plastic insulation is 0.72 inches.
Explanation:
Given that,
Diameter = 0.091 in
Thickness = 0.02 in
Initial temperature = 90°F
Final temperature = 50°F
Heat transfer coefficient = 2.5 Btu/h.ft²°F
Material conductivity = 0.075 Btu/h.ft °F
We need to calculate the critical radius of the plastic insulation
Using formula of critical radius
[tex]r_{cr}=\dfrac{2K}{h}[/tex]
Where, k = Material conductivity
h = Heat transfer coefficient
Put the value into the formula
[tex]r_{cr}=\dfrac{2\times0.075}{2.5}[/tex]
[tex]r_{cr}=0.06\ ft[/tex]
[tex]r_{cr}=0.72\ inches[/tex]
Hence, The critical radius of the plastic insulation is 0.72 inches.
A classroom is about 3 meters high, 20 meters wide and 30 meters long. If the density of air is 1.29 kg/m3, what is the mass of the air in the classroom?
Answer:
the mass of the air in the classroom = 2322 kg
Explanation:
given:
A classroom is about 3 meters high, 20 meters wide and 30 meters long.
If the density of air is 1.29 kg/m3
find:
what is the mass of the air in the classroom?
density = mass / volume
where mass (m) = 1.29 kg/m³
volume = 3m x 20m x 30m = 1800 m³
plugin values into the formula
1.29 kg/m³ = mass
1800 m³
mass = 1.29 kg/m³ ( 1800 m³ )
mass = 2322 kg
therefore,
the mass of the air in the classroom = 2322 kg
If A classroom is about 3 meters high, 20 meters wide and 30 meters long. If the density of air is 1.29 kg/m3, then the mass of the air in the classroom is 2322Kg.
What is density??Density is the ratio of mass to volume. it tells how much mass a body is having for its unit volume. for example egg yolk has 1027kg/m³ of density, means if we collect numbers of egg yolk and keep it in a container having volume 1 m³ then total amount of mass it is having will be 1027kg. Density is a scalar quantity. when we add egg yolk into the water, egg yolk has greater density than water( 997 kg/m³), because of higher density of egg yolk it contains higher mass in same volume as water. hence due to higher mass higher gravitational force is acting on the egg yolk therefore it goes down on the inside the water. water will float upon the egg yolk. same situation we have seen when we spread oil in the water. ( in that case water has higher density than oil. thats why oil floats on the water).
Given,
Height = 3 m
Width = 20 m
length= 30 m
Density of air = 1.29kg/m³
The volume of the room = 3×20×30 m³
Volume V = 1800m³
By formula,
Density = Mass/Volume
1.29kg/m³ = Mass/1800m³
Mass of the air = 1.29×1800 = 2322 Kg
The mass of the air is classroom is 2322Kg.
To know more about density :
https://brainly.com/question/29775886
#SPJ2.
How many meters are in 5.0 cm?
500
0.050
0.0005
0.5
Explanation:
100cm=1m
5 cm= x
cross multiple
x=5/100
=0.05m
There are 0.05 meters in 5 cm. The correct option among the following is option (B).
In the metric system, a centimeter (cm) is a unit of length. It is one centimeter (1 cm = 0.01 m) in size. Small distances or measurements, such as the length, height, or width of items, are frequently measured in centimeters. Due to its practical size for many routine measurements, it is also frequently employed in scientific and mathematical computations.
In the International System of Units (SI), the meter serves as the base unit and is frequently used to measure lengths, heights, and other measurements. It serves as the basic building block for other metric units like centimeters (one meter equals one hundred centimeters) and kilometers (one kilometer equals one thousand meters).
So, to convert 5.0 cm to meters:
5.0 cm ÷ 100 = 0.05 m
Hence, 5.0 cm is equal to 0.05 meters. The correct option is (B).
To learn more about meters, here:
https://brainly.com/question/13187866
#SPJ4
A car travels 20 meters east
in 1.0 second and then travels
10 meters west in 20 seconds. The
displacement of the car at the end
of this 3.0-second interval is-
Answer:
Alright the other day.
Which has the fastest wave speed, a high frequency sound or a low frequency sound?
Answer:
high frequent sound
Explanation:
because if its low than its slower.
What is a statement ?
1. Looking at the planet vs. eccentricity table, which two planets have the greatest eccentricity?
Answer:
Pluto & Mercury
Explanation:
Pluto's eccentricity is 0.248
Mercury's eccentricity is 0.206
The chilled water system for a 27-story building has a pump located at ground level. The lost head in a vertical riser from the pump to an equipment room on the twenty-seventhfloor is 40ftof water, and the pump produces 270ft of head. What is the pressure on the suction side of the pump for a pressure of 8 psig to exist in the riser on the twenty-fifth floor
This question is incomplete, the complete question is;
The chilled water system for a 27-story building has a pump located at ground level. The lost head in a vertical riser from the pump to an equipment room on the twenty-seventh floor is 40ft of water, and the pump produces 270ft of head. What is the pressure on the suction side of the pump for a pressure of 8 psig to exist in the riser on the twenty-fifth floor
Assume 12ft of elevation per floor
Answer: 48.68 psig
Explanation:
First we calculate the elevation of the building
hb = 27 story * 12ft per floor/story
hb = 324 ft
given that the head lost in the vertical riser hL = 40 ft
now the delivery head required in the riser on he 27th floor;
hd = 8 psig * (2.31 ft / 1 psig)
hd = 18.46 ft
Now calculate the suction head required by balancing the energy per unit weight of water, considering pump as the control volume
hp = (hb + hL + hd) - hs
hs = hb + hL + hd - hp
where hp is the head developed by the pump (270 ft)
hb is the elevation of the 27th floor of the building ( 324 ft)
hL is the head lost in the vertical riser ( 40 ft)
hd is the head required to exist in the riser on the 27th floor (18.46 ft)
so we substitute
hs = 324 ft + 40 ft + 18.46 ft - 270 ft
hs = 112.46
so 112.46ft * (1 psig / 2.31 ft)
= 48.68 psig
Which is a benefit of using synthetic polymers, such as nylon?
Synthetic polymers are lightweight.
O Synthetic polymers are produced in small
quantities.
Synthetic polymers are biodegradable.
Synthetic polymers are inexpensive to recycle.
Answer: Synthetic polymers are lightweight.
Explanation:
A benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
A polymer is a molecule composed of many repeating subunits.
Synthetic polymers are artificial polymers created by humans.
Most of the synthetic polymers are not biodegradable (unlike natural fibers such as cotton).
Synthetic polymers are classified according to their use into plastics, elastomers and synthetic fibers.
The advantages of synthetic polymers include: hard to break, being lightweight, and they last for a long time.
In conclusion, a benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
Learn more in:
https://brainly.com/question/4047007?referrer=searchResults
An automobile is driven on a straight road, and the distance traveled by the automobile after time t=0 is given by a quadratic function a where a(t) is measured in feet and t is measured in seconds for 0 <= t <= 12. Of the following, which gives the best estimate of the velocity of the automobile, in feet per second, at time t = 8 seconds?
a. s(8)
b. s(8)/8
c. s(12)- s(2)/ 12-2
d. s(9)- s(7)/9-7
Answer:
[tex]Velocity = \frac{s(8)}{8}[/tex]
Explanation:
Given
[tex]0 \leq t \leq 12[/tex]
Required
Determine the velocity when t = 8
This type of velocity is referred to as an instantaneous velocity.
In this case, it is calculated using
[tex]Velocity = \frac{Distance\ at\ 8 second}{t = 8}[/tex]
Given that s(t) models the distance;
s(8) = distance at 8 seconds
So;
[tex]Velocity = \frac{s(8)}{8}[/tex]
Option B answers the question
The overall length of a piccolo is 30.0 cm. The resonating air column is open at both ends. (a) Find the frequency of the lowest note a piccolo can sound. (Assume that the speed of sound in air is 343 m/s.) Hz (b) Opening holes in the side of a piccolo effectively shortens the length of the resonant column. Assume the highest note a piccolo can sound is 3 000 Hz. Find the distance between adjacent antinodes for this mode of vibration.
Answer:
(a) the frequency of the lowest note the piccolo can sound is 571.7 Hz
(b) the distance between adjacent antinodes is 5.72 cm
Explanation:
(a)
Given;
length of piccolo, L = 30 cm = 0.3 m
the speed of sound in air is 343 m/s
The wavelength of a pipe open at both ends, for the first harmonic is given;
L = A → N + N → A
L = λ / 4 + λ / 4
L = λ / 2
λ = 2L
λ = 2 x 0.3 = 0.6 m
The fundamental frequency (lowest frequency) is given by;
f₀ = v / λ
f₀ = (343 / 0.6)
f₀ = 571.7 Hz
(b)
Given;
highest note, f = 3000 Hz
the distance between adjacent antinodes is given by;
[tex]d = \frac{v}{2f}\\\\ d = \frac{343}{2*3000}\\\\ d = 0.0572 \ m\\\\d = 5.72 \ cm[/tex]
The Shinkansen (bullet train in Japan) makes a trip from Tokyo Station to Kyoto station in 2 hours and 14 min. The distance traveled is 460 km (to two significant figures). Determine the average velocity of the train in meters per second (m/s). [conversions: 1 km = 1000 m, 1 hr = 60 min, 1 min = 60 s] *
Answer:
v = 57.2 m/s
Explanation:
The average velocity of the train can be defined as the total distance covered by the train divided by the time taken by the train to cover that distance. Therefore, we will use the following formula to find the average velocity of the train:
v = s/t
where,
s = distance covered = 460 km = (460 km)(1000 m/1 km) = 4.6 x 10⁵ m
t = time taken to cover the distance = 2 h 14 min
Now, we convert it into minutes:
t = (2 h)(60 min/1 h) + 14 min
t = 120 min + 14 min = (134 min)(60 s/1 min)
t = 8040 s
Therefore, the value of velocity will be:
v = (4.6 x 10⁵ m)/8040 s
v = 57.2 m/s
Convert 2536 mm/min to m/s. Use dimensional analysis.
Answer:
As we know that,
1 mm/min = 1.66667E-5 m/s1 m/s = 60000 mm/minNow, come to the question -
[tex] \\ \implies \sf \: 2536 \times 1.66667E-5 m/s \\ \\ \\ \implies \sf \blue{0.0422666667 \:m/s } \\ [/tex]
Result : 2536 mm/min = 0.0422666667 m/s.
4. What is the velocity of an object that doesn't move?
It depends on the object b. it depends on the speed c. it depends on the height
O mis
help
Answer:
Acceleration /Speed
Explanation:
An objects Velocity can be determined by acceleration,
Please pay attention in your middle school class, speed and velocity quiz.
- When a mixture contains substances that are not evenly mixed, it is called?
Answer: Heterogenous mixture
Explanation:
A heterogeneous mixture in which the components of the mixture are not evenly mixed or uniform, allowing one to identify the different constituents of each components and enable the mixture to be separated physically.
Examples of heterogeneous mixtures includes
-- sand and nails
---rice and beans
--- water and oil
Another type of mixture is the homogeneous mixture in which all the components are evenly mixed causing that each components cannot be visible with the eye and therefore separated chemically.
What is normalization
Answer:
Normalization is a systematic approach of decomposing tables to eliminate data redundancy. It is a multi-step process that puts data into tabular form, removing duplicated data from the relation tables.
Explanation:
Answer:
the process of bringing or returning something to a normal condition or state.
Explanation:
In "your own words"- Normalization is when you change something back into it's average form.
5. Why does a properly adjusted head restraint help prevent head and neck injuries to occupants in
rear-end collisions? Explain your answer in terms of the law of conservation of momentum.
Answer:
Have you tried google
Explanation:
Answer:
protect against whisplasg injuries
what type of organism does not use photosynthesis
(a) plants
(b) bacteria
(c) algae
(d) humans
Answer:
D) Humans
Explanation:
Photosynthesis is a useless ability without some way of exposing yourself to as much of the Sun's energy as possible. That requires a large surface area, relative to their volume. Plants achieve that with large, horizontal, light-capturing surfaces – leaves.
The mass of a string is 20 g and it has a length of 3.2 m. Assuming that the tension in the string is 2.5 N, what will be the wavelength of a travelling wave that is created by a sinusoidal excitation of this string with a frequency of 20 Hz. Provide the wavelength in units of m. Please note: You do not include the units in your answer. Just write in the number.
Answer:
The wavelength of the wave is 1 m
Explanation:
Given;
mass of the string, m = 20 g = 0.02 kg
length of the string, L = 3.2 m
tension on the string, T = 2.5 N
the frequency of the wave, f = 20 Hz
The velocity of the wave is given by;
[tex]v = \sqrt\frac{T}{\mu} {}[/tex]
where;
μ is mass per unit length = 0.02 kg / 3.2 m
μ = 6.25 x 10⁻³ kg/m
[tex]v = \sqrt{\frac{T}{\mu} } \\\\v = \sqrt{\frac{2.5}{6.25*10^{-3}} } \\\\v = 20 \ m/s[/tex]
The wavelength of the wave is given by;
λ = v / f
λ = (20 m/s )/ (20 Hz)
λ = 1 m
Therefore, the wavelength of the wave is 1 m
I need with the basic understanding of this
Answer:
A = air resistance
B = lift
C = thrust
D = gravity
1.00 N, 2.86° above horizontal
Explanation:
Gravity pulls down on the bird. The thrust of the birds wings push it forward, and the lift pushes it up. Air resistance pushes it back.
The net force in the y direction is:
∑Fᵧ = lift − gravity
∑Fᵧ = 0.20 N − 0.15 N
∑Fᵧ = 0.05 N
The net force in the x direction is:
∑Fₓ = thrust − air resistance
∑Fₓ = 1.50 N − 0.50 N
∑Fₓ = 1.00 N
The magnitude of the resultant force is:
F² = Fₓ² + Fᵧ²
F² = (1.00 N)² + (0.05 N)²
F ≈ 1.00 N
The direction of the resultant force is:
tan θ = Fᵧ / Fₓ
tan θ = (0.05 N) / (1.00 N)
θ = 2.86° above horizontal
Oppositely charged parallel plates are separated by 4.49 mm. A potential difference of 600 V exists between the plates. (a) What is the magnitude of the electric field between the plates? N/C (b) What is the magnitude of the force on an electron between the plates? N (c) How much work must be done on the electron to move it to the negative plate if it is initially positioned 3.14 mm from the positive plate?
Answer:
A. Using
E=V/d
= 600/4.49*10^-3
= 1.336 x10^5 N/C
b) F = E*q = 1.33610^5 x 1.6*10^-19
= 2.17 x 10^-14 N
c) Work = Fs distance = 2.17 x 10^-14 N (4.49-3.14)*.001= 1.35 x 10^-17 J
One of the specific goals of of environmental analysis is:____________
a: To provide organized information, for the development of the organization's internal analysis, mission, vision , values and strategy.
b: To measure organizational efficiency.
c: To ignore minor competitors.
d: To develop a list of "one-word: descriptions of the external environment.
Answer:
a: To provide organized information, for the development of the organization's internal analysis, mission, vision, values, and strategy.
Explanation:
Environmental analysis is a process in business wherein the internal and external factors that can affect a business are examined so as to help improve the organization's goals and strategies. The internal analysis serves as a guide to checkmate the organization and to see if they have adopted the right strategies that suit their external environment.
Competitors in the external environment can have a huge impact on the business. So the internal workings of the organization should align with the external factors. The organized information would also be useful in forecasting the growth of the business.
An electron enters a region of uniform electric field with an initial velocity of 64 km/s in the same direction as the electric field, which has magnitude E = 48 N/C. (a) What is the speed of the electron 1.3 ns after entering this region? (b) How far does the electron travel during the 1.3 ns interval?
Answer:
1.) 11 km/s
2.) 9.03 × 10^-5 metres
Explanation:
Given that an electron enters a region of uniform electric field with an initial velocity of 64 km/s in the same direction as the electric field, which has magnitude E = 48 N/C.
Electron q = 1.6×10^-19 C
Electron mass = 9.11×10^-31 Kg
(a) What is the speed of the electron 1.3 ns after entering this region?
E = F/q
F = Eq
Ma = Eq
M × V/t = Eq
Substitute all the parameters into the formula
9.11×10^-31 × V/1.3×10^-9 = 48 × 1.6×10^-19
V = 7.68×10^-18 /7.0×10^-22
V = 10971.43 m/s
V = 11 Km/s approximately
(b) How far does the electron travel during the 1.3 ns interval?
The initial velocity U = 64 km/s
S = ut + 1/2at^2
S = 64000×1.3×10^-6 + 1/2 × 8.4×10^12 × ( 1.3×10^-9)^2
S =8.32×10^-5 + 7.13×10^-6
S = 9.03 × 10^-5 metres
The group that receives treatment is called the?
Tested Group
Control Group
Placebo Group
Experimental Group
Answer:
experimental group
Explanation:
please mark me as a brainlist..
Answer:
Experemtial group
Explanation:
The placebo is just sugar pills tested is ones already done and control is a mix of the two
A car travels 82 meters do North and 14 seconds the car turns around and travels 44 m due south in four seconds what is the magnitude of the average velocity of the car during the full travel time?
Answer:
2.11 m/s
Explanation:
Take north to be positive and south to be negative.
Average velocity = displacement / time
v = (82 m + -44 m) / (14 s + 4 s)
v = 2.11 m/s
The velocity is positive, so it is 2.11 m/s north. The magnitude of the velocity is 2.11 m/s.
Aldis is swinging a ball tied to the end of a string over his head. Suddenly, the string breaks and the ball flies away. Arrow best represents the path the ball follows after the string breaks.
Answer:
Straight line in the direction of the tangential velocity the ball had at the moment the string broke
Explanation:
After the string breaks, the ball now disconnected from the centripetal force that was exerted via the string, continues its travel in a straight line in the direction of the tangential velocity it had at the moment the string broke.
Answer:
B
Explanation:
just took the test :)
the graph shows position versus time for an object moving with the constant acceleration. what is the final velocity of the object at t=10s? assume the initial velocity at the origin is 1 m/s.
3.32 m/s
4.0 m/s
3.0 m/s
3.8 m/s
Answer:
3.0 m/s
Explanation:
The equation of motion for constant acceleration (a) is ...
[tex]x(t)=\dfrac{1}{2}at^2 +v_0t+x_0[/tex]
The problem statement tells us v₀ = 1, and we read from the graph that x₀=1. We also read from the graph that x(10) = 21. Filling these values into the equation, we can find a and x'(10).
[tex]21 = \dfrac{1}{2}a(10^2)+1(10)+1\\\\10=50a\qquad\text{subtract 11}\\\\a=\dfrac{1}{5}\\\\x'(t)=at+v_0\\\\x'(10)=\dfrac{1}{5}\cdot 10+1=3.0[/tex]
The final velocity of the object at t=10 s is about 3.0 m/s.
_____
Comment on the graph
We note this graph better represents increasing acceleration than it does constant acceleration. x(2) = 3.4 per the equation. It is graphed as about 4.
Answer:
thanks for de points
Explanation:
what role do control groups play
Answer:
Control groups let the one who is expermenting compare the effect of the varibles in the expermental group.
Explanation:
A cyclist accelerates from rest to 8 m/s in 3 seconds. How far did the cycles travel in 3 seconds?
Answer:
[tex] \boxed{\sf Distance \ travelled = 12 \ m} [/tex]
Given:
Initial speed (u) = 0 m/s (Accelerates from rest)
Final speed (v) = 8 m/s
Time taken (t) = 3 seconds
To Find:
Distance travelled by cyclist (s)
Explanation:
From equation of motion of object moving with uniform acceleration in straight line we have:
[tex] \boxed{ \bold{s = (\frac{v + u}{2} )t}}[/tex]
By substituting value of v, u & t in the equation we get:
[tex] \sf \implies s = ( \frac{8 + 0}{2} ) \times 3 \\ \\ \sf \implies s = \frac{8}{2} \times 3 \\ \\ \sf \implies s = 4 \times 3 \\ \\ \sf \implies s = 12 \: m[/tex]
[tex] \therefore[/tex]
Distance travelled by cyclist (s) = 12 m
Answer:
s(distance) =36m
Explanation:
u(initial velocity) =0 m/s
a =8 m/s^2
t=3s
s=ut+1/2at^2
s=1/2(8)(3)^2
s=1/2(8)(3)(3)
s=4(9)
s=36m
where do plants get the energy they need for photosynthesis
(A) leaves
(B) the sun
(C) sugars
(D) water
they get their energy from photosynthesis, so the answer would be (B) the sun
How did oxygen get into the earths atmosphere in its early days? plz explain
Answer:
The answer is tiny organisms known as cyanobacteria, or blue-green algae. These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen. In fact, all the plants on Earth incorporate symbiotic cyanobacteria (known as chloroplasts) to do their photosynthesis for them down to this day.
Explanation: