Answer:
Explanation:
1) weight = mg = 9.81*1000 = 9810 Newtons
2) frictional force = normal force *
we must assume that the vehicle is on a flat surface so therefore the normal force is the same as the weight of the vehicle.
frictional force = 9810 * 0.55 = 5 395.5 N
3) acceleration: F = ma, a = F/m
assume that only the frictional force is acting on the vehicle:
a = 5395.5/1000 = 5.3955 m/s
4) the car decelerates at 5.3955m/s
over 6 seconds, the car decelerates by: 32.37m/s
5) original speed = 29m/s final speed = 29-32.37 = -3.37m/s which is a negative number, therefore the vehicle would have stopped before it hit the rail.
6) to get to the rail, the vehicle would have had to be traveling at least 32.37m/s which is 72.41 mph
10- The voltage across the generator of
the circuit of figure 13 is 12V and
the voltmeter V2 indicates 8V:
А
ס
N.
V
L1
L2
B
L
Fig.13
a- What would the voltmeter V3 indicate?
Justify the answer
b- What would the voltmeter Vi indicate?
Justify the answer
hey! i just wanted to ask if you found the answer because i’m looking for it
The heat loss from a boiler is to be held at a maximum of 900Btu/h ft2 of wall area. What thickness of asbestos (k= 0.10 Btu/h ft ℉) is required if the inner and outer surfaces of the insulation are to be 1600 and 500℉, respectively? Now if a 3-in.-thick layer of kaolin brick (k= 0.07 Btu/h ft ℉) is added to the outside of the asbestos, what heat flux will be result if the outside surface of the kaolin is 250℉? What will be the temperature at the interface between the asbestos and kaolin for this condition?
Answer:
a. 0.122 ft b. -70 Btu/h ft² c. 633.33 °F
Explanation:
a. Since the rate of heat loss dQ/dt = kAΔT/d where k = thermal conductivity, A = area, ΔT = temperature gradient and d = thickness of insulation.
Now [dQ/dt]/A = kΔT/d
Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), ΔT = T₂ - T₁ = 500 °F - 1600 °F = -1100 °F. We need to find the thickness of asbestos, d. So,
d = kΔT/[dQ/dt]/A
d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²
d = 0.122 ft
b. If the 3 in thick Kaolin is added to the outside of the asbestos, and the outside temperature of the asbestos is 250℉, the heat loss due to the Kaolin is thus
[dQ/dt]/A = k'ΔT'/d'
k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft
[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft
[dQ/dt]/A = -70 Btu/h ft²
c. To find the temperature at the interface, the total heat flux equals the individual heat loss from the asbestos and kaolin. So
[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d' where [dQ/dt]/A = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), k' = 0.07 Btu/h ft ℉(for Kaolin), T₁ = 1600 °F, T₂ = unknown and T₃ = 250℉.
Substituting these values into the equation, we have
-900Btu/h ft² = 0.10 Btu/h ft ℉(T₂ - 1600 °F)/0.122 ft + 0.07 Btu/h ft ℉(250℉ - T₂)/0.25 ft
-900Btu/h ft² = 0.82 Btu/h ft ℉(T₂ - 1600 °F) + 0.28Btu/h ft ℉(250℉ - T₂)
-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82T₂ - 1312°F + 70 °F - 0.28T₂
collecting like terms, we have
-900 °F + 1312°F - 70 °F = 0.82T₂ - 0.28T₂
342 °F = 0.54T₂
Dividing both sides by 0.54, we have
T₂ = 342 °F/0.54
T₂ = 633.33 °F
The thickness of asbestos required is 0.122 ft.
The heat flux will be -70 Btu/h ft²
And the temperature of the interface is 633.33 °F.
(i) the rate of heat loss :
dQ/dt = kAΔT/d
where k = thermal conductivity, A = area, ΔT = temperature gradient, and
d = thickness of insulation.
[dQ/dt]/A = kΔT/d
Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft²,
k = 0.10 Btu/h ft ℉,
ΔT = 500 °F - 1600 °F = -1100 °F
We have to find the thickness of asbestos that is d.
d = kΔT/[dQ/dt]/A
d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²
d = 0.122 ft is the thickness required.
(ii) a 3-in thick Kaolin is added to the outside of the asbestos
outside temperature of the asbestos is 250℉,
the heat loss due to the Kaolin is:
[dQ/dt]/A = k'ΔT'/d'
k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft
[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft
[dQ/dt]/A = -70 Btu/h ft²
(iii) temperature at the interface
the total heat flux :
[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d'
where [dQ/dt]/A = -900 Btu/h ft²,
k = 0.10 Btu/h ft ℉ (for asbestos),
k' = 0.07 Btu/h ft ℉ (for Kaolin),
T₁ = 1600 °F and T₃ = 250℉.
-900 = 0.10(T₂ - 1600 °F)/0.122 + 0.07(250℉ - T₂)/0.25
-900 = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82T₂ - 1312°F + 70 °F - 0.28T₂
-900 °F + 1312°F - 70 °F = 0.82T₂ - 0.28T₂
342 °F = 0.54T₂
Dividing both sides by 0.54, we have
T₂ = 342 °F/0.54
T₂ = 633.33 °F
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A family drives 881 miles from Houston Texas to Santa Fe New Mexico for vacation how long will it take the family to reach their destination if they travel at a velocity of 55.0 miles per hour northwest?
Answer:
about 16 hours
Explanation:
if driving 55mph for 16 hrs you will travel about 880 miles
True or False: Heavy elements such as Carbon and Nitrogen, that are necessary for life were created in the Big
Bang and have been around in the Universe since that time.
Answer:
i believe the answer is true
Explanation:
everything was created in the big bang
what is Newton's second law?
F=mXa
a=F/m
m=F/a
All of the above
It should be the first one, F= mXa (F = m times a).
A planned high-speed train between Houston and Dallas will travel a distance of 386 kilometers in 5.40 × 10^3 seconds. What is the average speed of this train?
¡Hellow!
For this problem, first, lets convert the seconds in hours:
5,4x10³[tex]\rightarrow[/tex] 5400
h = sec / 3600
h = 5400 s / 3600
h = 1,5
Let's recabe information:
d (Distance) = 386 km
t (Time) = 1,5 h
v (Velocity) = ?
For calculate velocity, let's applicate formula:
[tex]\boxed{\boxed{\textbf{d = v * t} } }[/tex]
Reeplace according we information:
386 km = v * 1,5 h
v = 386 km / 1,5 h
v = 257,33 km/h
The velocity of the train is of 257,33 kilometers for hour.
Extra:
For convert km/h to m/s, we divide the velocity of km/h for 3,6:
m/s = km/h / 3,6
Let's reeplace:
m/s = 257,33 km/h / 3,6
m/s = 71,48
¿Good Luck?
Q. If space is vaccumed then how moon is attracted to earth by it gravity?
Answer:
The vacuum of outer space is not caused by the expansion of the universe, but is caused by gravity.
Explanation:
Gizmo seasons why do we have them answer key
A
1. Runners A, B, and C are running a race. Based on their locations, which 20 points
runner is experiencing acceleration?
Answer:
B) 48 metres
Explanation:
Three identical 6.4kg masses are hung by three identical springs. Each spring has a force constant of 7.8 Kn/m and is 12cm long before any masses are attached to it. how long is the bottom most spring going to be after the three masses are hung on it
a. 14.3 b. 16.2 c.12.8 d.10.7
Answer:
The correct option is;
c. 12.8 cm
Explanation:
The given parameters are;
The length of each spring = 12 m = 0.12 m
Given that the masses and the springs are vertically oriented, we have;
The mass on the first spring = 3 × 6.4 = 19.2 kg
The weight on the first spring = 19.2 kg × 9.81 m/s² = 188.352 N
The extension of the first spring = 188.352 N/7,800 N/m ≈ 0.02415 m
The mass on the second spring = 2 × 6.4 = 12.8 kg
The weight on the second spring = 12.8 kg × 9.81 m/s² = 125.568 N
The extension of the second spring = 125.568 N/7,800 N/m ≈ 0.016098 m
The mass on the third spring = 1 × 6.4 = 6.4 kg
The weight on the third spring = 6.4 kg × 9.81 m/s² = 62.784 N
The extension of the third (bottom) spring = 62.784 N/7,800 N/m ≈ 0.00805 m
The total length of the bottom spring = Original length of the bottom spring + Extension of the bottom spring
The total length of the bottom spring ≈ 0.12 m + 0.00805 m = 0.12805 m
The total length of the bottom spring ≈ 0.12805 m ≈ 12.81 cm
The bottom spring will be approximately 12.81 cm long.
someone help me with this please
Answer: are u single
Explanation:
What's the time it takes a car to attain the speed of 30 m/s when accelerating from rest at 2 m/s (squared)
A- 15 s
B- 2 s
C- 60 s
D- 30 s
E- none
what are some hack that I can use to heal up my eyes?
Answer:
All 7 Dragonballs
Explanation:
the dragonball Summon shenron which will then grant you a wish
Which of the following statements is true?
Solar eclipses are safe to look at without special equipment.
The International Date Line runs through Greenwich, England.
New days begin at 180° longitude.
Earth's orbit is a perfect circle.
Answer:
New days begin at 180° longitude.
Explanation:
What is the pressure on a surface when a 20 N force is applied 10 m2, 5 m2, 2 m2
A gas is compressed to 75cm3 to a volume of 30cm3. Its temperature remains the same The pressure of the gas after it has been compressed is 110 Pa. What was the pressure before it was compressed?
Given parameters:
Initial volume = 75cm³
New volume = 30cm³
New pressure = 110Pa
Unknown:
Initial pressure = ?
Solution:
Condition: temperature is constant
We simply apply Boyle's law to this problem:
" the volume of a fixed mass(mole) of a gas varies inversely as the pressure changes if the temperature is constant".
Mathematically;
P₁ V₁ = P₂ V₂
where P and V are pressure and volume values
1 and 2 are the initial and final states.
Input the parameters and solve for P₁;
P₁ x 75 = 110 x 30
P₁ = 44Pa
The initial pressure is 44Pa
A rock is dropped off a cliff and strikes the ground with an impact velocity of 20m/s. How high was the cliff?(use a=-10m/s2)
Answer:
20 m
Explanation:
by the formula,
[tex]2aS = V_{f}^{2} - V_{i}^2[/tex]
2 x 10 x S = 20^2 - 0
20S = 400
[tex]S = \frac{400}{20}[/tex]
S = 20 m
+ 9. What force (in units of Newtons) is needed to give a 3.5 m/s" acceleration to a 1200 kg car?
Answer:
4200 Newtons
Explanation:
Force = mass x acceleration
1200 x 3.5 = 4200
Drag the tiles to the correct boxes to complete the pairs.
Match the organisms to the descriptions.
scorpion
starfish
octopus
bird
lacks colored blood
had a soft, unsegmented body
is a vertebrate
lacks antennae
The correct matching of the organisms to their descriptions is given below:
Starfish - lacks colored bloodBird - is a vertebrateOctopus - has a soft, unsegmented bodyScorpion - lacks antennaeWhat is an Organism?Any organic, living system that performs as an independent unit is referred to as an organism. Cells comprise all living things. Multicellular mammals, plants, and fungi are examples of multicellular creatures. Unicellular microorganisms include bacteria and archaea.
All kinds of creatures can have the capacity for procreation, growth and development, maintenance, and to some extent, stimulus-response. Multicellular organisms such as beetles, tetrapods, mushrooms, and vascular plants grow a variety of tissues and organs.
Read more about vertebrates here:
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Please, can any one help
Answer:
a = 1.458 [m/s²]
Explanation:
To be able to solve this type of problems it is always advisable to make a free body diagram with the forces acting on the body.
Attached is an image with the free body diagram and the proposed equations, the explanation of obtaining the equations will be described below.
Let's take the movement to the left as positive, i.e. all forces going to the left have a positive sign.
Let's use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
To the left we have the two forces of tension by the cosine of the angle. And to the right the frictional force. The resultant of these forces is equal to the product of the mass (mass of the child plus the mass of the sled), by acceleration.
It takes 39.7 N to push a crate at a constant speed across flat ground where μk=0.438 what is the mass of the crate
Answer:
I don't know how to show the work but I just had this question and the answer is 9.24kg.
Explanation:
Explain how mass and velocity play a big role in the amount of momentum an object has.
Answer:
Momentum is directly proportional to the object's mass and also its velocity. Thus the greater an object's mass or the greater its velocity, the greater its momentum. Momentum p is a vector having the same direction as the velocity v. The SI unit for momentum is kg · m/s.
Answer:
Momentum is directly proportional to the object's mass and also its velocity. Thus the greater an object's mass or the greater its velocity, the greater its momentum. Momentum p is a vector having the same direction as the velocity v. The SI unit for momentum is kg · m/s.
Explanation:
What is the legal height the player is allowed to serve from a. Above the waist B. Below the waist C. On the waist D. above the chest
Answer: Option B.
Explanation:
I guess that this refers to the Badminton rules, particularly to the position of the racket (or the head of the racket, where the "head" is the part with the net, that you use to hit the shuttle) when serving.
The head of the racket must be swung from below your waist. So the head of the racket must be below your waist before you do the service (With a part of the head is enough).
Then the correct option is B. Below the waist.
An airplane lands with an initial velocity of 60 m/s and then slows down at 1.5 m/s2 for 30 seconds. What is its final velocity?
a. 3 m/s
b. 15 m/s
c. 98 m/s
d. 105 m/s
A toyota prius can go from 0 m/s to 30 m/s in 15 s. What is its acceleration? Select one: O 15 m/s2 O 2 m/s2 450 m/s2 30 m/s2
Answer:
I think it is 2m/s2
Explanation:
Have a great day:)
How are the layers of the Earth similar and different from one another?
Answer:
the innermost layer of the earth
Explanation:
the earth has an outer core liquid and an inner core solid they are not chemically distinct from each other but they are chemically distinct from the mantle the core is mainly composed of nickel and iron
HELP FAST PLEASE. NEWTON'S LAWS.
which statements describes a chemical property
Answer:
a chemical property can be observed without changing the identity of the substance.
Explanation:
a physical property is a characteristic that can be observed without changing the substance into another substance. The object reacts with acid to form water.
Write a short story where the main character needs protection from two different EM radiations
???whats the answers??
The answers is 30 miles per hour, the driver is speeding the car up, section-H, 12 minutes, section-D, and 65 miles per hour.