Answer:
0.064 mg/kg/day
6.25% from water, 93.75% from fish
Explanation:
Density of water is 1 kg/L, so the concentration of the chemical in the water is 0.1 mg/kg.
The BCF = 10³, so the concentration of the chemical in the fish is:
10³ = x / (0.1 mg/kg)
x = 100 mg/kg
For 2 L of water and 30 g of fish:
2 kg × 0.1 mg/kg = 0.2 mg
0.030 kg × 100 mg/kg = 3 mg
The total daily intake is 3.2 mg. Divided by the woman's mass of 50 kg, the dosage is:
(3.2 mg/day) / (50 kg) = 0.064 mg/kg/day
b) The percent from the water is:
0.2 mg / 3.2 mg = 6.25%
And the percent from the fish is:
3 mg / 3.2 mg = 93.75%
A household refrigerator with a COP of 1.2 removes heat from the refrigerated space at a rate of 60kJ/min. Determine: (a) The electric power consumed by the refrigerator, and (b) The rate of heat transfer to the kitchen air.
Answer:
a) Power =50 KJ/min
b)Rate of heat transfer = 110 KJ/min
Explanation:
Given that
COP = 1.2
Heat removed from space Q = 60 KJ/min
As we know that COP of refrigerator is the ratio of heat removed to work input.
Lets take power consume by refrigerator is W
So
COP= Q/W
1.2=60/W
W=50 KJ/min
So the power consume is 50 KJ/min.
From first law of thermodynamic
Heat removed from the kitchen = 50 + 60 KJ/min
Heat removed from the kitchen =110 KJ/min
Convert each of the following to three significant figures: (a) 20 lb.ft to N.m, (b) 450 Ib/ft^3 to kN/m^3, and (c) 15 ft/h to mm/s.
Answer:
(a)27.12 N-m (b) 69.96 [tex]KN/m^3[/tex] (c) 1.27 mm/sec
Explanation:
We have to convert
(a) 20 lb-ft to N-m
We know that 1 lb = 4.45 N
So 20 lb = 20×4.45 = 89 N
1 feet = 0.3048 m
So [tex]20lb-ft=20\times 4.45N\times 0.3048N=27.12N-m[/tex]
(b) 450 [tex]lb/ft^3[/tex] to KN/[tex]m^3[/tex]
We know that 1 lb = 4.45 N = 0.0044 KN
[tex]1ft^3=0.0283m^3[/tex]
So [tex]450lb/ft^3=\frac{450\times 0.0044KN}{0.0283m^3}=69.96KN/m^3[/tex]
(c) 15 ft/hr to mm/sec
We know that 1 feet = 0.3048 m = 304.8 mm
And 1 hour = 60×60=3600 sec
So [tex]15ft/h=\frac{15\times 304.8mm}{3600sec}=1.27 mm/sec[/tex]
Answer:
a)20 lb.ft=27.2 N.m
b)[tex]450\dfrac{lb}{ft^3}=70.65\dfrac{KN}{m^3}[/tex]
c)15 ft/h = 1.26 mm/s
Explanation:
a)
As we know that
1 ft.lb= 1.36 N.m
So 20 lb.ft = 1.36 x 20 N.m
20 lb.ft=27.2 N.m
b)
We know that
[tex]1\dfrac{lb}{ft^3}=0.157\dfrac{KN}{m^3}[/tex]
So
[tex]450\dfrac{lb}{ft^3}=450\times 0.157\dfrac{KN}{m^3}[/tex]
[tex]450\dfrac{lb}{ft^3}=70.65\dfrac{KN}{m^3}[/tex]
c)
As we know that
1 ft/h=0.084 mm/s
So
15 ft/h = 0.084 x 15 mm/s
15 ft/h = 1.26 mm/s
(a) If 15 kW of power from a heat reservoir at 500 K is input into a heat engine with an efficiency of 37%, what is the power output? (b) What is the temperature of the cold reservoir?
Explains how to calculate power output and cold reservoir temperature for a heat engine.
Explanation:Given:
Power input: 15 kWHeat reservoir temperature: 500 KEfficiency: 37%(a) Calculation of Power Output:
The efficiency formula for a heat engine is Efficiency = (Useful work output / Heat input). Power output can be calculated as Power output = Efficiency * Power input.
(b) Calculation of Temperature of Cold Reservoir:
Using the Carnot efficiency formula, you can find the cold reservoir temperature when the efficiency of the real heat engine is known.
Draw and write shear strain equation
Answer:
[tex]\phi =\dfrac{\Delta L}{h}[/tex]
Explanation:
Normal strain :
It is the ratio of deformation to the original dimension.Normal strain occurs due to longitudinal force.
Normal strain = ΔL/L
Shear strain:
It is the ratio of deformation to perpendicular dimension.Shear strain occurs due to tangential force.
From the second diagram:
[tex]tan\phi =\dfrac{\Delta L}{h}[/tex]
if angle Φ is small then we can write
[tex]tan\phi =\phi[/tex]
So
[tex]\phi =\dfrac{\Delta L}{h}[/tex]
This is the shear strain equation.
Relation between Poisson's ration, young's modulus, shear modulus for an isotropic material
Answer:
E=2 G(1+2μ)
Explanation:
Isotropic material :
Those material have same property in all direction is known as isotropic material.
Homogeneous material :
Those material have same property through out the volume is known as homogeneous material.
Relationship between Poisson ratio ,young modulus and shear modulus:
E=2 G(1+2μ)
Relationship between Poisson ratio ,bulk modulus and shear modulus:
E=2 K(1-μ)
Where
E is young modulus.
G is shear modulus.
μ is Poisson ratio.
A circular piston exerts a pressure of 80kPa on a fluid
whenthe force applied to the piston is 0.2kN . Find the diameter of
thepiston.
Answer:
Diameter of the piston will be [tex]3.1847\times 10^{-3}m[/tex]
Explanation:
We have given force F = 0.2 kN = 200 N
Pressure P = 80 kPa = 80000 pa
We have to find the diameter of the piston
We know that [tex]pressure = \frac{force}{area }=\frac{200}{80000}=2.5\times 10^{-3}m^2[/tex]
We know that area of circular piston is given by [tex]A=\pi r^2[/tex]
So [tex]2.5\times 10^{-3}=3.14\times r^2[/tex]
[tex]r=1.5923\times 10^{-3}m[/tex]
We know that diameter d = 2×radius =[tex]d=1.5923\times 10^{-3}\times 2=3.1847\times 10^{-3}m[/tex]
How do you define a renewable energy source? Why are coal, oil, and natural gas not renewable energy sources?
Answer:
Explanation:
A renewable energy source is one that can not depelted in a reasonable timeframe.
Sun energy will last until the Sun dies, which is expected to haen in about 5 billion years. Because it will last so long it is considered practiacally eternal and undepleteable.
Fossil fuels on the other hand are material deposits in the crust of Earth that might be depleted within centuries.
A renewable energy source can be replenished rapidly and is not permanently consumed by human use, examples include solar and wind energy. Fossil fuels like coal, oil, and natural gas are non-renewable because they take millions of years to form and are finite. Sustainable energy use does not exhaust resources and can continue over time.
Explanation:A renewable energy source is defined as one that can be replenished in a short amount of time and is not permanently depleted by human usage. Renewable resources include things like solar and wind energy, which are continually available through natural processes such as sunlight and wind currents.
Coal, oil, and natural gas are not considered renewable energy sources because they are formed over millions of years from the buried remains of plants and animals. These fossil fuels are finite and once consumed, they do not replenish in a timeframe that is practical for human use, thereby classifying them as non-renewable.
When we use renewable resources, they offer a sustainable way to generate energy. Sustainable means using methods that do not completely use up or destroy natural resources, therefore capable of continuing for a long time. Examples of methods to harness renewable resources include solar panels for sunlight, wind turbines for wind, and hydroelectric power stations for flowing water.
Consider a single pane window. The dimensions of the ¼-inch-thick glass window pane are about 0.9 m by 1.65 m. The surface temperatures of the glass will not be equal to the air temperature on the respective sides, as will be seen later in the course. For these conditions, the glass surface temperatures are approximately 1°F and -7°F. (At this time, we do not have the HT skills to calculate the surface temperatures.) Determine the heat transfer rate vector through the glass for these surface temperatures. Express your answer in vector notation. Your sketch should identify your coordinate system and your vector answer should agree with your sketch. For consistency, set your coordinate system such that the inside glass surface is at the origin and the outside surface is in the positive x direction (typically to the right!).
Answer:
q = (709*K*i + 0*j + 0*k)
Explanation:
1/4 inch is 6.35 mm = 0.00635 m
A = 0.9 * 1.65 = 1.48 m^2
t1 = 1 F = -17.2 C
t2 = -7 F = -21.7 C
The heat will be conducted through the glass. We use a frame of reference with the origin on the warmer side of the glass (t1) and the positive X axis pointing perpendicular to the glass towards the colder side.
The Fourier equation for plates (one dimensional form) is:
q = -K * dT / dx
We can simplify dT/dx to ΔT/Δx if we assume the temperature changes linearly through the glass.
q = -K * ΔT/Δx
K is the thermal conductivity of the glass
ΔT = t2 - t1
ΔT = -21.7 + 17.2 = -4.5 C
Δx is the thickness of the glass
q = -K * -4.5 / 0.00635
q = 709 * k
The vector is: q = (709*K*i + 0*j + 0*k)
It has no components in Y or Z because there if no variation of temperature in those directions (the temperature of the glass is given as each face having a constant temperature throughout its area).
The temperature at which the polymer becomes viscous is called: glass transition temperature (Tg). a)-True b)- false?
Answer:
a)True
Explanation:
The temperature at which the polymer becomes viscous is called glass transition temperature.
When polymer is heated then it will become viscous and temperature is called glass transition temperature.
Glass temperature depends on the chemical structure of the polymer.
Polymer are made of long change structure and these change are connected together one by one and form a complex structure.
Example -Rubber or elastomer,Plastics.
Determine the mass of a car that weight 3,500 lbs both in slugs and kilograms. The answer should be in kilograms.
Answer:
The mass of car in slug =108.5 slug.
The mass of car in kilogram =1575 Kg.
Explanation:
Given that
Mass of car = 3500 lbs
We know that
1 lbs =0.031 slug
So
3500 lbs = 0.031 x 3500 slug
So the mass of car in slug =108.5 slug.
We know that
1 lbs =0.45 kilograms
so
3500 lbs = 3500 x 0.45 Kg
So the mass of car in kilogram =1575 Kg.
Specific internal energy is measured in energy per unit mass dimensions. What is 310 kJ/kg in Btu/lbm units?
Answer:
133.276 Btu/lbm
Explanation:
1 kJ/kg = 0.429923 Btu/lbm
Therefore, 310 kJ/kg = 133.276 Btu/lbm
Specific internal energy can be defined as the internal energy (kJ or Btu) divided by a unit of mass (kg or lbm). Both sets of units (kJ/kg and Btu/lbm) are units for specific energy.
Energy is an object's ability to do work and is represented in this example in Joules (J) or British Thermal Units (Btu).
1 kJ = 1000 J
Mass tells us how much something weighs and is represented in this example in kg or lbm (pounds).
Please define the specific heat of material?
Answer and Explanation:
SPECIFIC HEAT :
Specific heat is denoted by [tex]c_v[/tex]It is the heat required for increasing the temperature of a substance which has mass of 1 kg.Its SI unit is joule/kelvinIt is physical property It can be calculated by [tex]c_v=\frac{Q}{m\Delta T}[/tex], here Q is heat energy m is mass of gas and [tex]\Delta T[/tex] is change in temperature.What is centrifugal force with respect to unbalance? What is the formula used to determine centrifugal force?
Answer:
[tex]F = \frac{m * v^2}{r}[/tex]
Explanation:
Once the centrifugal forces are equivalent as an object rotates, it is called "in equilibrium." If the point of impact of the moving object does not align with the center of the rotation, unequal centrifugal forces are produced and the rotating component is "out of equilibrium."
Two conditions for balanced condition are: static and coupled. Static equilibrium relates to a one plane mass in which the unit is balanced by weight inverse the unbalanced mass
formula used to calculate centrifugal mass is [tex]F = \frac{m * v^2}{r}[/tex]
where, m is mass, v is speed of body. r is radius
Consider a cylindrical nickel wire 2.1 mm in diameter and 3.2 × 104 mm long. Calculate its elongation when a load of 280 N is applied. Assume that the deformation is totally elastic and that the elastic modulus for nickel is 207 GPa (or 207 × 109 N/m2).
Answer:
Total elongation will be 0.012 m
Explanation:
We have given diameter of the cylinder = 2.1 mm
Length of wire [tex]L=3.2\times 10^4mm[/tex]
So radius [tex]r=\frac{d}{2}=\frac{2.1}{2}=1.05mm=1.05\times 10^{-3}m[/tex]
Load F = 280 N
Elastic modulus = 207 Gpa
Area of cross section [tex]A=\pi r^2=3.14\times (1.05\times 10^{-3})^2=3.461\times 10^{-6}m^2[/tex]
We know that elongation in wire is given by [tex]\delta =\frac{FL}{AE}[/tex], here F is load, L is length, A is area and E is elastic modulus
So [tex]\delta =\frac{FL}{AE}=\frac{280\times 32}{3.461\times 10^{-6}\times 207\times 10^9}=0.012m[/tex]
You are hitting a nail with a hammer (mass of hammer =1.8lb) the initial velocity of the hammer is 50 mph (73.33 ft/sec). The time of impact is .023 sec. Assuming the nail heads directly in the -j direction, what is the magnitude of the force exerted on the hammer from the nail?
Answer:
The nail exerts a force of 573.88 Pounds on the Hammer in positive j direction.
Explanation:
Since we know that the force is the rate at which the momentum of an object changes.
Mathematically [tex]\overrightarrow{F}=\frac{\Delta \overrightarrow{p}}{\Delta t}[/tex]
The momentum of any body is defines as [tex]\overrightarrow{p}=mass\times \overrightarrow{v}[/tex]
In the above problem we see that the moumentum of the hammer is reduced to zero in 0.023 seconds thus the force on the hammer is calculated using the above relations as
[tex]\overrightarrow{F}=\frac{m(\overrightarrow{v_{f}}-\overrightarrow{v_{i}})}{\Delta t}[/tex]
[tex]\overrightarrow{F}=\frac{m(0-(-73.33)}{0.23}=\frac{1.8\times 73.33}{0.23}=573.88Pounds[/tex]
A tensile force of 9 kN is applied to the ends of a solid bar of 7.0 mm diameter. Under load, the diameter reduces to 5.00 mm. Assuming uniform deformation and volume constancy, (a) determine the engineering stress and strain; (b) determine the true stress and strain.
Answer:
Explanation:
Given
Force=9 kN
Diameter reduces from 7 mm to 5 mm
As volume remains constant therefore
[tex]A_0L_0=A_fL_f[/tex]
[tex]7^2\times L_0=5^2\times L_f[/tex]
[tex]\frac{L_0}{L_f}=\frac{25}{49}[/tex]
Thus Engineering Strain [tex]\epsilon _E=\frac{L_f-L_0}{L_0}[/tex]
[tex]=\frac{49}{25}-1=\frac{49-25}{25}=0.96[/tex]
Engineering stress[tex]=\frac{Load}{original\ Cross-section}[/tex]
[tex]\sigma _E=\frac{9\times 10^3}{\frac{\pi 7^2}{4}}=233.83 MPa[/tex]
(b)True stress
[tex]\sigma _T=\sigma _E\left ( 1+\epsilon _E\right )[/tex]
[tex]\sigma _T=233.83\times (1+0.96)=458.30 MPa[/tex]
True strain
[tex]\epsilon _T=ln\left ( 1+\epsilon _E\right )[/tex]
[tex]\epsilon _T=ln\left ( 1.96\right )=0.672[/tex]
We discover a nearby star with two planets. The first planet has an orbit period of 10 years and is in a circular orbit with radius 106 km. The second planet has an orbit period of 15 years. What is its orbit radius? You may assume it is also in a circular orbit.
Answer: 139 Km.
Explanation:
The question tells us that a planet A has an orbit period of 10 years and its circular orbit has a radius of 106 Km, whilst a planet B has an orbit period of 15 years (also assuming a circular orbit), both orbiting a nearby star.
This information allow us to use the Kepler's 3rd law, for the special case in which the orbit is circular.
Kepler's 3rd law, tells that there exist a direct proportionality between the square of the orbit period, and the cube of the orbit radius (in the more general case, with the cube of the semi-major axis of the elipse), for celestial bodies orbiting a same star.
(like Earth and Mars orbiting Sun).
So, for planet A and planet B (orbiting a same star), we can write the following:
(TA)²/ (TB)² = (rA)³ / (rB)³
Replacing by TA= 10 years, TB= 15 years, rA= 106 Km, and solving for Rb, we get RB= 139 Km.
What is 1000 kJ/sec in watts?
Answer:
1000000 watts
Explanation:
1 kJ/sec= 1000 watts (or 1 watt= 0.001 kJ/sec)
Therefore,
1000 kJ/sec = 1000 x 1000 watts
= 1000000 watts
A kJ/sec (Kilojoule per second) is a unit used to measure power. It comes from the SI (Standard International) unit J/sec (Joule per second).
1 J/sec= 1 watt
Power is the energy transferred by a force per unit of time.
Energy is measured in Joules.
In this question, we are working out how much energy is transferred in watts.
A satellite would have a mass of 270 kg on the surface of Mars. Determine the weight of the satellite in pounds if it is in orbit 15,000 miles above the surface of the Earth.
Answer:
26 lbf
Explanation:
The mass of the satellite is the same regardless of where it is.
The weight however, depends on the acceleration of gravity.
The universal gravitation equation:
g = G * M / d^2
Where
G: universal gravitation constant (6.67*10^-11 m^3/(kg*s))
M: mass of the body causing the gravitational field (mass of Earth = 6*10^24 kg)
d: distance to that body
15000 miles = 24140 km
The distance is to the center of Earth.
Earth radius = 6371 km
Then:
d = 24140 + 6371 = 30511 km
g = 6.67*10^-11 * 6*10^24 / 30511000^2 = 0.43 m/s^2
Then we calculate the weight:
w = m * a
w = 270 * 0.43 = 116 N
116 N is 26 lbf
Describe the differences between convection and thermal radiation.
Answer:
Explanation:
Convection needs a fluid to transport the heat, while radiation doesn't.
Generally convection transports a lot more heat than radiation.
Since fluids tend to expand, when in a gravitational field such as that of Earth convection tends to move heat upwards while radiation is indifferent to gravity.
An insulated rigid tank contains 5 kg of a saturated liquid-vapor mixture of water at a. Initially, three-quarters of the mass is in the liquid phase. An electric resistor placed in the tank is connected to a 110-V source, and a current of 8 A flows through the resistor when the switch is turned on. (a) Determine how much time it will take to vaporize all the water in the tank, and (b) show the process on a T-v diagram with respect to the saturation lines.
Answer:
2.67 hours
Explanation:
If three quarters of the mass are in liquid phase, I have a mass of water:
m1 = 3/4 * 5 = 3.75 kg
The latent heat of vaporization of water is of
ΔHvap = 2257 kJ/kg
The heat needed to vaporize it is:
Q = m * ΔHvap
Q = 3.75 * 2257 = 8464 kJ
If I have a resistor connected to 110 V, with a current of 8 A, the heat it dissipates through Joule effect will be:
P = I * V
P = 8 * 110 = 880 W = 0.88 kW
With that power it will take it
t = Q / P
t = 8464/0.88 = 9618 s = 160 minutes = 2.67 hours2.
A motocycle starts from rest at t = 0.0 on a circular track
of400 meter radious. The tangential component of acceleration
isat=2+0.2t m/sec^2. At time t =10 sec determine
thedistance the motorcycle has moved along the track and the
magnitudeof its acceleration. (Knowing that a=at
+an).
Answer:
[tex]S_{10}=133.3m\\a_{10}=4.589m/s^{2}[/tex]
Explanation:
In order to know the value of the speed at any time t, we need to integrate the acceleration. Once we get the speed vs time, we need to integrate again to get the distance traveled by the motorcycle vs time. So let's start with the speed first:
[tex]V(t) = \int {a(t)} \, dt = \int {2+0.2*t} \, dt = 2*t + 0.2*\frac{t^{2}}{2}[/tex]
We will integrate once again to get distance:
[tex]S(t) = \int {V(t)} \, dt = \int {2*t+0.2*\frac{t^{2}}{2} } \, dt = t^{2}+0.2*\frac{t^{3}}{6}[/tex]
Now we just need t evaluate S(10s):
S(10) = 133.3m
For the acceleration, we know that:
[tex]a = \sqrt{a_{t}^{2}+a_{N}^{2}}[/tex]
where [tex]a_{t}(10)=2+0.2*(10)=4m/s^{2}[/tex]
and [tex]a_{N}(10)=\frac{V(10)^{2}}{R}=2.25m/s^{2}[/tex]
So, finally:
[tex]a = \sqrt{a_{t}^{2}+a_{N}^{2}} = 4.589m/s^{2}[/tex]
Do a summary what happen to titanic in the aspect of material(body) and the ductile brittle temperature (DBT) of the material.
Explanation:
A ductile material can convert into brittle material due to following reasons
1.At very low temperature
2.Due to presence of notch
In titanic ,the base of ship strike to the large ice cube and lower part of titanic ship material was made of steel .We know that steel is ductile material and when steel came with very low temperature of ice due to this ductile material converted in to brittle material and titanic ship failed.Brittle material does not show any indication before failure.
Can someone work this problem out completly?
A 3 kg model rocket is launched vertically and reaches
andaltitude of 60 m wih a speed of 28 m/s at the end of flight,
timet=0. As the rocket approaches its maximum altitude itexplodes
into two parts of masses Ma = 1 kg and Mb = 2 kg. Part A is
observed to strike the ground 74.4 m west of the launchpoint at t =
5.85 s. Determine the position of part B at thattime.
Answer:
Part B will be 37.2 m to the east of the launch point at an altitude of 80.8 m
Explanation:
At t0 the rocket is at 60 m and has a speed of 28 m/s.
Then it explodes when it reaches max altitude.
Since the rocket will have its engine off after t0 it will be in free fall.
It will be affected only by the acceleration of gravity, so it moves with constant acceleration, we can use this equation.
Y(t) = Y0 + V0*t + 1/2*a*t^2
Y0 = 60 m
V0 - 28 m/s
a = g = -9.81
We also have the equation for speed:
V(t) = V0 + a*t
And we know that when it reaches its highest point it ill have a speed of zero.
0 = V0 + a * t
a * t = -V0
t = -V0 / a
t = -28 / -9.81 = 2.85 s
This is the time after t0 when the engine ran of of fuel.
Using this value on the position equation:
Y(2.85) = 60 + 28*2.85 + 1/2*(-9.81)*2.85^2 = 100 m
At an altitude of 100 m it explodes in two parts. An explosion is like a plastic collision in reverse, momentum is conserved.
Since the speed of the rocket is zero at that point, the total momentum will be zero too.
Part A, with a mass of 1 kg fell 74.4 m west of the launch point. It fell in a free fall with a certain initial speed given to it by the explosion. This initial speed had vertical and horizontal components.
First the horizontal. In the horizontal there is no acceleration (ignoring aerodynamic drag).
X(t) = X1 + Vx1 * (t - t1)
X1 = 0 because it was right aboce the launch point. t1 is the moment of the explosion.
t1 = 2.85 s
We know it fell to the ground at t = 5.85 s
Vx1 * (t2 - t1) = X(t2) - X1
Vx1 = (X(t2) - X1) / (t2 - t1)
Vx1 = (74.4 - 0) / (5.85 - 2.85) = 24.8 m/s
Now the vertical speed
Y(t2) = Y1 + Vy1*(t2 - t1) + 1/2*a*(t2 - t1)^2
Vy1*(t2 - t1) = Y(t2) - 1/2*a*(t2 - t1)^2 - Y1
Y(t2) = 0 because it is on the ground.
Vy1 = (-1/2*a*(t2 - t1)^2 - Y1) / (t2 - t1)
Vy1 = (-1/2*-9.81*(5.85 - 2.85)^2 - 100) / (5.85 - 2.85) = -18.6 m/s
If the part A had a speed of (24.8*i - 18.6*j) m/s, we calcultate the speed of part 2
Horizontal:
vxA * mA + vxB * mB = 0
-vxA * mA = vxB * mB
vxB = -vxA * mA / mB
vxB = -24.8 * 1 / 2 = -12.4 m/s
Vertical:
vyA * mA + vyB * mB = 0
-vyA * mA = vyB * mB
vyB = -vyA * mA / mB
vyB = -(-16.6) * 1 / 2 = 8.3 m/s
Now that we know its speed and position at t1 we can know ehre it will be at t2
X(t) = 0 - 12.4 * (t - t1)
X(5.85) = -12.4 * (5.85 - 2.85) = -37.2 m
Y(t) = 100 + 8.3 * (t - t1) + 1/2 * (-9.8) * (t - t1)^2
Y(t) = 100 + 8.3 * (5.85 - 2.85) + 4.9 * (5.85 - 2.85)^2 = 80.8 m
Part B will be 37.2 m to the east of the launch point at an altitude of 80.8 m
By increasing the cross-sectional area of the restriction, one can significantly increase the flow velocity. a) True b) False
Answer:
b)false
Explanation:
As we know that
Volume flow rate Q
Q = A x V
For constant volume flow rate,if velocity will increase then automatically area will decrease and vice versa.
Generally nozzle are used to increase the velocity and diffuser are used to decrease the exit velocity of flow.
So by increasing the cross sectional area of the restriction ,the velocity of the flow will decrease.
A fluid flows through a pipe of constant circular cross-section diameter 1.1m with a mean velocity of 50cm/s. The mass flow rate of the flow through the pipe, given by the formula mass flow rate = (density) (mean velocity) (cross - sectional area), is measured to be 110 kg/s. Find the specific gravity, specific weight and specific volume of the fluid.
Answer:
Explanation:
Given
diameter(d)=1.1 m
mean velocity(u)=50 cm/s
mass flow rate(m)=110 kg/s
[tex] A=0.950 m^2[/tex]
[tex]m=\rho \cdot A\cdot u[/tex]
where [tex]\rho [/tex] =density of fluid
[tex]110=\rho \times 0.95\times 0.5[/tex]
[tex]\rho =231.46 kg/m^3[/tex]
Therefore specific gravity[tex]=\frac{\rho }{\rho _{water}}[/tex]
[tex]=\frac{231.46}{1000}=0.231[/tex]
Specific weight[tex]=\rho \cdot g=231.46\times 9.81=2270.70 kg/m^2-s^2[/tex]
specific volume[tex]=\frac{1}{density}[/tex]
[tex]=\frac{1}{231.46}=0.00432 m^3/kg[/tex]
The hoist of a crane consists of a 10 kW electric motor running at 1440 rpm drivine 300 mm diameter drunn through a 60:1 gear reduction unit. If the efficiency is 90% . calculate the load, in tonnes that can be lifted at the rated motor capacity, and the lifting speed.
Answer:
Load = 2.42 tons
Lifting speed = 24 RPM
Explanation:
Given that
Power=10 KW
Efficiency = 90%
So the actual power,P=0.9 x 10 =9 KW
Speed of motor = 1440 RPM
Diameter of drum = 300 mm
radius =150 mm
G=60:1
Lets take speed of drum =N
We know that
[tex]G=\dfrac{Speed\ of\ motor}{Speed\ of\ drum}[/tex]
[tex]60=\dfrac{1440}{N}[/tex]
N=24 RPM
We know that
[tex]P=\dfrac{2\pi NT}{60}[/tex]
Where T is the torque
[tex]9000=\dfrac{2\pi \times 24\times T}{60}[/tex]
T=3580.98 N.m
Lets take load =F
So T= F x r
3580.98 = F x 0.15
F=23.87 KN
We know that
1 KN=0.109 tons
So 23.87 KN= 2.42 tons
So the load = 2.42 tons
Lifting speed = 24 RPM
Which of carbon will have higher strength but less ductility, 0.49% or 0.19%
Answer:
0.49%
Explanation:
Assuming this is about steel. Higher carbon steel tend to be harder and stronger, but that hardness makes them more brittle and less ductile. This is because with higher carbon concentrations there is more formation of pearlite, which has higher hardness than ferrite. Pearlite contains layers of cementite, which is a fragile material, so the presence of these microstructures will make the whole thing more brittle.
Four kilograms of gas were heated at a constant pressure of 12 MPa. The gas volumes were 0.005 m^3 and 0.006 m^3 in the initial and final states, respectively, and 3.9 kJ of heat was transferred to the gas. What is the change in specific internal energy between the initial and final states?
Answer:
Specific change in internal energy is - 2.025 kj/kg.
Explanation:
The process is constant pressure expansion. Apply first law of thermodynamic to calculate the change in internal energy.
Given:
Mass of gas is 4 kg.
Initial volume is 0.005 m³.
Final volume is 0.006 m³.
Pressure is 12 Mpa.
Heat is transfer to the gas. So it must be positive 3.9 kj.
Calculation:
Step1
Work of expansion is calculated as follows:
[tex]W=P(V_{f}-V_{i})[/tex]
[tex]W=12\times10^{6}(0.006-0.005)[/tex]
W=12000 j.
Or,
W=12 Kj.
Step2
Apply first Law of thermodynamic as follows:
Q=W+dU
3.9=12+dU
dU = - 8.1 kj.
Step3
Specific change in internal energy is calculated as follows:
[tex]u=\frac{U}{m}[/tex]
[tex]u=\frac{-8.1}{4}[/tex]
u= - 2.025 kj/kg.
Thus, the specific change in internal energy is - 2.025 kj/kg.
A round steel bar, 0.02 m in diameter and 0.40 m long, is subjected to a tensile force of 33,000 kg. Y=E= 2E10 kg/m^2. (modulus).Calculate the elongation in meters.
The elongation of the steel bar under the given tensile force is approximately 2.10 millimeters.
The cross-sectional area (A) of the steel bar can be calculated using the formula for the area of a circle:
A = π * r²
Now, let's calculate A:
A = π * (0.01 m)²
≈ π * (0.0001 m²)
≈ 0.000314 m²
Now, we can calculate the elongation (ΔL) using Hooke's Law:
ΔL = (F * L) / (A * E)
Given:
F = 33,000 kg
L = 0.40 m
E = 2 * 10¹⁰ kg/m²
Now, plug in the values:
ΔL = (33,000 kg * 0.40 m) / (0.000314 m² * 2 * 10₈⁰ kg/m²)
Now, perform the calculation
ΔL ≈ (13,200 kg*m) / (6.28 * 10 kg/m²)
ΔL ≈ 2.10 * 10⁻₀ meters