Answer:
9.60%
Explanation:
Computation for the weight fraction of graphite
First step
Computation for the mass fraction for Wa using this formula
Wa=Cg-Co/Cg-Ca
Let plug
Wa=10-3/100-0
Wa=0.97
Computation for the mass fraction for Wg using this formula
Wg=Co-Ca/Cg-Ca
Let plug in the formula
Wg=3-0/100-0
Wg=0.03
Second step is to convert the mass fraction to Volume Fraction using this formula
Volume Fraction =[Wg/Pg÷(Wa/Pa)+(Wg/Pg)]*100
Let plug in the formula
Volume =[0.03/2.3 ÷(0.97/7.9)+(0.03/2.3)]*100
Volume=[0.0130435÷0.1227848+0.0130435]*100
Volume=[0.0130435÷0.135828]*100
Volume=0.096*100
Volume=9.60%
Therefore the weight fraction of graphite will be 9.60%
A person walks into a refrigerated warehouse with head uncovered. Model the head as a 25- cm diameter sphere at 35°C with a surface emissivity of 0.95. Heat is lost from the head to the surrounding air at 25°C by convection with a convection coefficient of ???????????????? ???????? ????????????????∙???????? , and by radiation to the surrounding black walls at 15°C. Determine the total rate of heat loss. StefanBoltzmann Constant, ???????? = ????????. ???????????????? × ????????????????−???????? ???????? ????????????????∙???????????????? . (10 points)
Answer:
Hello some parts of your question is missing below is the missing part
Convection coefficient = 11 w/m^2. °c
answer : 44.83 watts
Explanation:
Given data :
surface emissivity ( ε )= 0.95
head ( sphere) diameter( D ) = 0.25 m
Temperature of sphere( T ) = 35° C
Temperature of surrounding ( T∞ ) = 25°C
Temperature of surrounding surface ( Ts ) = 15°C
б = ( 5.67 * 10^-8 )
Determine the total rate of heat loss
First we calculate the surface area of the sphere
As = [tex]\pi D^{2}[/tex]
= [tex]\pi * 0.25^2[/tex] = 0.2 m^2
next we calculate heat loss due to radiation
Qrad = ε * б * As( [tex]T^{4} - T^{4} _{s}[/tex] ) ---- ( 1 )
where ;
ε = 0.95
б = ( 5.67 * 10^-8 )
As = 0.2 m^2
T = 35 + 273 = 308 k
Ts = 15 + 273 = 288 k
input values into equation 1
Qrad = 0.95 * ( 5.67 * 10^-8 ) * 0.2 ( (308)^4 - ( 288)^4 )
= 22.83 watts
Qrad ( heat loss due to radiation ) = 22.83 watts
calculate the heat loss due to convection
Qconv = h* As ( ΔT )
= 11*0.2 ( 35 -25 ) = 22 watts
Hence total rate of heat loss
= 22 + 22.83
= 44.83 watts
a cantilever beam 1.5m long has a square box cross section with the outer width and height being 100mm and a wall thickness of 8mm. the beam carries a uniform load of 6.5kN/m along the entire length and, in the same direction, a concentrated force of 4kN at the free end. (a) determine the max bending stress (b) determine the max transervse shear stress (c) determine the max shear stress in the beam
Answer:
a) 159.07 MPa
b) 10.45 MPa
c) 79.535 MPa
Explanation:
Given data :
length of cantilever beam = 1.5m
outer width and height = 100 mm
wall thickness = 8mm
uniform load carried by beam along entire length= 6.5 kN/m
concentrated force at free end = 4kN
first we determine these values :
Mmax = ( 6.5 *(1.5) * (1.5/2) + 4 * 1.5 ) = 13312.5 N.m
Vmax = ( 6.5 * (1.5) + 4 ) = 13750 N
A) determine max bending stress
б = [tex]\frac{MC}{I}[/tex] = [tex]\frac{13312.5 ( 0.112)}{1/12(0.1^4-0.084^4)}[/tex] = 159.07 MPa
B) Determine max transverse shear stress
attached below
ζ = 10.45 MPa
C) Determine max shear stress in the beam
This occurs at the top of the beam or at the centroidal axis
hence max stress in the beam = 159.07 / 2 = 79.535 MPa
attached below is the remaining solution
An astronomer of 65 kg of mass hikes from the beach to the observatory atop the mountain in Mauna Kea, Hawaii (altitude of 4205 m). By how much (in newtons) does her weight change when she goes from sea level to the observatory?
Answer:
[tex]0.845\ \text{N}[/tex]
Explanation:
g = Acceleration due to gravity at sea level = [tex]9.81\ \text{m/s}^2[/tex]
R = Radius of Earth = 6371000 m
h = Altitude of observatory = 4205 m
Change in acceleration due to gravity due to change in altitude is given by
[tex]g_h=g(1+\dfrac{h}{R})^{-2}\\\Rightarrow g_h=9.81\times(1+\dfrac{4205}{6371000})^{-2}\\\Rightarrow g_h=9.797\ \text{m/s}^2[/tex]
Weight at sea level
[tex]W=mg\\\Rightarrow W=65\times 9.81\\\Rightarrow W=637.65\ \text{N}[/tex]
Weight at the given height
[tex]W_h=mg_h\\\Rightarrow W_h=65\times 9.797\\\Rightarrow W_h=636.805\ \text{N}[/tex]
Change in weight [tex]W_h-W=636.805-637.65=-0.845\ \text{N}[/tex]
Her weight reduces by [tex]0.845\ \text{N}[/tex].
A plate and frame heat exchanger has 15 plates made of stainless steel that are 1 m tall. The plates are 1 mm thick and 0.6 m wide and are spaced 4.8 mm apart. The exchanger is used to cool water. The volume flow rate of this water is 0.011 m3/s, and its inlet temperature is 30 C. Raw water is the cooling medium. It enters the exchanger at 6 C with a volume flow rate of 0.02 m3/s. Calculate the outlet temperatures.
Answer:
14.506°C
Explanation:
Given data :
flow rate of water been cooled = 0.011 m^3/s
inlet temp = 30°C + 273 = 303 k
cooling medium temperature = 6°C + 273 = 279 k
flow rate of cooling medium = 0.02 m^3/s
Determine the outlet temperature
we can determine the outlet temperature by applying the relation below
Heat gained by cooling medium = Heat lost by water
= ( Mcp ( To - 6 ) = Mcp ( 30 - To )
since the properties of water and the cooling medium ( water ) is the same
= 0.02 ( To - 6 ) = 0.011 ( 30 - To )
= 1.82 ( To - 6 ) = 30 - To
hence To ( outlet temperature ) = 14.506°C
Help please and please
Determine the size of memory needed for CD recording of a piece of music, which lasts for 26 minutes, is done with a 20-bit Analog-to-Digital Converter (ADC) in stereo (2 channels), at the rate of 44.1 kSa/s, with the compression factor 6 (allow 10% error margin).
Answer: the size of memory needed for the CD recording is 28.7 MB
Explanation:
so in the case of stereo, the bitrate is;
⇒ 26 × 60 × 44.1 × 10³ × 2
= 137592 × 10³
for 10 bit
⇒ 137592 × 10³ × 10
= 1375920 × 10³ bits
now divide by 8 (convert to bytes)
⇒ (1375920 × 10³) / 8
= 171,990,000 BYTE
divide by 1000 (convert to kilobytes)
= 171,990,000 / 1000
= 171,990 KILOBYTES
now Given that, the compression ratio is 6
so
171,990 / 6
= 28665 KB
we know that. 1 MB = 1000 KB
x MB = 28665 KB
x MB = 28665 / 1000
⇒ 28.665 MB ≈ 28.7 MB
Therefore the size of memory needed for the CD recording is 28.7 MB
Select the correct answer.
Tires need to be regularly:
A.
Replaced
B.
Rotated
C.
Both A and B
D.
None of the above
A wedge would be best described as
A wheel and axle used to cTeate a rotary motion
A lever arm fixed to a shaft
A triangle shaped tool that functions as an inclined plane
A rectangular shaped tool that functions as a pulley
Answer:
A rectangular shaped tool that functions as a pulley.
Explanation:
i beleive
4.
error occurs when the measurement we think we see is not the
measurement being indicated by the instrument.
A. Positioning
B. Operator bias
C. Instrument
D. Observational
Answer: observational error
Explanation:
An Error occurs when the measurement is actually done by the Observational approach. Thus, the correct option is D.
What is an ideal method of measurement?The ideal methods of measurement are subdivided into two methods: They are as follows:
Direct measurement method.Indirect measurement method.The Direct measurement method involves the utilization of instruments such as micrometers, vernier calipers, coordinate measuring machines, etc. In this method, the unknown quantity is directly compared with the standard quantity.
In the Indirect measurement method, the physical parameter of the quantity is measured with the help of the direct method.
Positioning of the required quantity, operator-biased measurement, and the utilization of instruments for estimating the measurement of any unknown value are generally favored in order to eliminate the chances of errors.
Therefore, an Error occurs when the measurement is actually done by the Observational approach. Thus, the correct option is D.
To learn more about Errors in Measurement, refer to the link:
https://brainly.com/question/475573
#SPJ2
Estimate (a) the maximum, and (b) the minimum thermal conductivity values (in W/m-K) for a cermet that contains 76 vol% carbide particles in a metal matrix. Assume thermal conductivities of 30 and 67 W/m-K for the carbide and metal, respectively.
Answer:
The answer is below
Explanation:
Given that:
Volume of carbide ([tex]V_{C}[/tex]) = 76% = 0.76, Volume of Nickel ([tex]V_{M}[/tex]) = 100% - 76% = 24% = 0.24, thermal conductivities of carbide ([tex]E_{C}[/tex]) = 30 W/m-K and thermal conductivities of meta. ([tex]E_M[/tex]) = 67 W/m-K
a) The maximum thermal conductivity is given by:
Max = [tex]E_CV_c+E_mV_m=(0.76*30) + (0.24*67) = 38.88\ W/mK[/tex]
b) The minimum thermal conductivity is given by:
Min = [tex]\frac{E_ME_C}{E_MV_C+E_CV_M}=\frac{30*67}{(0.76*67)+(0.24*30)}=34.58\ W/mK[/tex]
is a street the same as a avenue
they're essentially the same thing so i'd say yes
Support with three reasons the decision to use a plastic material for the package in the following
scenario.
Situation: A client has hired Jose, a materials engineer, to develop a package for an item he has begun
to market. The object needs to be mailed to customers within three days of being ordered.
Answer:
its durable. it's cheap. its recyclable
Explanation:
Plastic is made of lots of recycled materials that make it very useful and cheap.
7. The process of separating a milk’s solids from its liquids is called
A. Homogenization
B. Curdling
C. Creaming
D. Baking
Answer: B is correct
Explanation:
the process in which dairies make cheese by separating a milk's solids from its liquid is called. curdling.
In a compression test, a steel test specimen (modulus of elasticity 30 106 lb/in2 ) has a starting height 2.0 in and diameter 1.5 in. The metal yields (0.2% offset) at a load 140,000 lb. At a load of 260,000 lb, the height has been reduced to 1.6 in. Determine (a) yield strength and (b) fl ow curve parameters (strength coeffi cient and strain-hardening exponent). Assume that the cross-sectional area increases uniformly during the test.
Answer:
A) σ_y = 79096 lb/in² = 79.1 ksi
B) strain-hardening exponent = 0.102
(strength coefficient = 137838.78 lb/in²
Explanation:
A) Formula for volume is;
V = πd²h/4
We are given;
height 2.0 in and diameter 1.5 in
Thus;
V = (π × 1.5² × 2)/4
V = 3.53 in³
Area is;
A = πd²/4
A = (π × 1.5²)/4
A = 1.77 in²
Yield strength is gotten from the formula;
σ_y = Force/Area
We are given load = 140,000 lb
Thus;
σ_y = 140000/1.77
σ_y = 79096 lb/in²
B) We are given
modulus of elasticity: E = 30 × 10^(6) lb/in²
Formula for strain is;
ε = σ_y/E
ε = 79096/(30 × 10^(6))
ε = 0.00264
The metal yields (0.2% offset), thus;
strain offsets = 0.00264 + 0.002
strain offsets: ε1 = 0.00464
Thus;
(h_i - h_o)/h_o = 0.00464
(h_i/h_o) - 1 = 0.00464
(h_i/h_o) = 1.00464
h_i = h_o(1.00464)
h_o = 2 in
Thus; h_i = 2(1.00464) = 2.00928 in
Area = Volume/height = 3.53/2.00928 = 1.757 in²
True stress is;
σ = force/area = 140000/1.757
σ1 = 79681.27 lb/in²
At a load of 260,000 lb, the height has been reduced to 1.6 in. Thus;
Area = 3.53/1.6 = 2.206 in²
True stress is;
σ2 = 260000/2.206
σ2 = 117860.38 lb/in²
True strain;
ε2 = In(2/1.6)
ε2 = 0.223
From flow curve;
σ = kεⁿ
Thus;
σ1 = k(ε1)ⁿ
79681.27 = k(0.00464ⁿ) - - - (eq 1)
Also for σ2 = k(ε2)ⁿ;
117860.38 = k(0.223ⁿ) - - - - - (eq 2)
From eq 1,
k = 79681.27/0.00464ⁿ
Putting this for k in eq2 to get;
117860.38 = (0.223ⁿ) × 79681.27/0.00464ⁿ
117860.38/79681.27 = 0.223ⁿ/0.00464ⁿ
Solving for n, we have ≈ 0.102
Thus,K is;
k = 79681.27/0.00464^(0.102)
k = 137838.78 lb/in²
Five identical keys are suspended from a balance, which is held horizontally as shown. The two keys on the left are attached to the balance 6 cm from the pivot and the three keys on the right are attached 5 cm from the pivot. What will happen when the person lets go of the balance beam?
Answer:
movement in clockwise direction.
Explanation:
The following parameters or information are given from the question above, they are:
[1]. There are two identical keys, [2]. two out of the five keys are attached to 6cm from the pivot, [3]. three keys out of the five keys on the right are attached 5 cm.
Therefore, considering the moment of force, the two keys on the left = 2 × 6 = 12.
Also, considering the moment of force, the 3 keys on the right = 3 × 5 = 15.
Therefore, we have more weight on the right keys. So, in order to balance the force there must be movement in clockwise direction.
The purpose of pasteurizing milk is to A. Kill pathogens B. Break down milk fat C. Add vitamins and minerals D. Prevent spoilage by sunlight
Answer:
The answer is A
Explanation:
The correct answer is A
How many flip-flop values are complemented in an 8-bit binary ripple counter to reach the next count value after: 0110111 and 01010110?
Answer:
- Four (4) flip-flop values will complemented
- one (1) flip-flop value will complemented
Explanation:
To find how many flip flop number of bits complemented, we just need to figure out what the next count in the sequence is and find how many bits have changed.
taking a look at the a) 00110111
we need to just 1 to the value,
so
00110111 + 0000001 = 00111000
So here, only the first four bits are complemented.
Therefore Four (4) flip-flop values will complemented
Next
b) 01010110
we also add 1 to the value
01010110 + 00000001 = 01010111
only the first bit is complemented.
Therefore one (1) flip-flop value will complemented
Select the correct answer.
Which chemical can you use to assist with your motor fuel needs?
O A.
ethylene glycol
OB.
ethanol
O c.
butanol
OD.
pentanol
O E.
propranolol
Reset
Next
Answer: Ethanol
Explanation:
4. The process of heating milk to kill microorganisms that cause spoilage and disease without affecting its nutritional value is called
A. Homogenization
B. Pasteurization
C. Boiling
D. Poaching
Answer:
I think the answer is C. Boiling but I'm not 100% sure.
If most wildfires are suppressed (all fires are put out) for many years, how does the risk of wildfire in the area change in the future?
There will be a higher risk of wildfires
There will be a lower risk of wildfires
There is no difference in risk
Explain your answer.
Answer:
there is no difference in risk
Explanation:
even though they put out the fires, if they don't get rid of the source from which the wildfires comes from then wildfires wont stop coming
Describe and compare the characteristics of (a) proportional control, (b) proportional plus integral control, (c) proportional plus integral plus derivative control.
Answer:
The answer is below
Explanation:
1. Proportional Control is a form of control engineering in which an output is directly proportional to the error signal.
Characteristics of proportional control are:
* It is utilized when the deviation between the input and output is small
* It is also utilized when the deviation is not sudden.
* It reduces steady-state error
* It speeds up the response of the overdamped system
2. Proportional plus Integral Control is a form of control engineering in which a collective proportion and integral control of the output is equivalent to the combined proportion and integral of the error signal.
Characteristics of proportional plus integral control are:
* it can revert the controlled variable to the original set point
* It decreases steady-state error
* It quickens up the reaction of the overdamped system
3. Proportional plus integral plus derivative control is mostly applicable in operating the process elements such as temperature, pressure, speed, etc. It is recommended for industrial use.
Characteristics of Proportional plus integral plus derivative control are:
* It enhances the temporary reaction of the system.
* It also lessens steady-state error
* It accelerates the response of the overdamped system
How is the law of conservation of matter best represented in a chemical reaction
Answer:
Umm.... because the spit that comes up of your mouth when you talk mixes with the air
Explanation:
Which of the following terms describes the path from an electrical source to a switch or plug?
transmitter
circuit breaker
raceway
breaker panel
Answer:
transmitter hope thus helped!
Explanation:
Raceway is the answer
"A raceway is an enclosed conduit that forms a physical pathway for electrical wiring."
Write 83,120 in expanded form using powers of 10.
Answer:
8*10000+3*1000+1*00+2*10+2
Explanation:
The purpose of pasteurizing milk is to
A. Kill pathogens
B. Break down milk fat
C. Add vitamins and minerals
D. Prevent spoilage by sunlight
Plis can someone help me ?
Answer:
i think it c
Explanation:
