Answer:
Vf = 25.7 [m/s]
Explanation:
To solve this problem we must use the following kinematics equation:
[tex]v_{f} ^{2}= v_{i} ^{2}-(2*a*x)[/tex]
where:
Vf = final velocity [m/s]
Vi = initial velocity = 30 [m/s]
a = desacceleration = 2 [m/s^2]
x = distance = 60 [m]
Note: the negative sign in the equation means that the car slows down.
Now replacing:
[tex]v_{f}^{2}=(30)^{2}-(2*2*60)\\ v_{f}^{2} = 660\\v_{f} =\sqrt{660} \\v_{f}=25.7[m/s][/tex]
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.
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
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
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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Gizmo seasons why do we have them answer key
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.
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.
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 distance between two spheres (20 kg and 30 kg) attracted by a force of 2 x 10^-5 Newtons.
Which of the following statments does not represent the relationship between culture and one's moral reasoning?
A.
Cultures generally differ in what behaviors are considered appropriate.
B.
One's thought and beliefs are generally independent of cultural influences.
C.
Many cultures value an individual's rights and well-being when establishing moral standards.
D.
Many cultures consider situational influences when judging one's behavior as right or wrong.
The only option that does not represent the relationship between culture and one's moral reasoning is one's thought and beliefs are generally independent of cultural influences.
What is culture?Culture can be defined as the people's way of life. It is an umbrella term which encompasses the social behavior and norms found in human societies.
Moral reasoning is the process by which people apply their thought or make judgment in analyzing issues and making decisions.
Thus, the only option that does not represent the relationship between culture and one's moral reasoning is one's thought and beliefs are generally independent of cultural influences.
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How to raise the awareness water saving
Answer:Lead by an example
Practice what you preach. You'll never convince anyone to conserve water if you aren't doing it yourself.
Engage with others.
Seek out allies.
Give people a reason to save.
Provide entry-level strategies.
Encourage others to challenge themselves.
Think big.
Choose a monthly focus.
+ 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
Which quantity is a vector?
displacement
distance
Olivia and Caitlyn want to know whether the wind affects how far a football will travel. They have one student go outside to the football field when it is not windy and throw the football 30 times. They measure how far the ball goes using a meter stick. On a windy day, they have the same student go to the football field and throw the football 30 times. Again, they measure how far the ball goes using the same meter stick. What is the Independent Variable?
Answer:
presence or absence of wind
Explanation:
When establishing a relationship between two variables the effect one variable has on the other is studied. The variable that changes with respect to the other is the dependent variable while the other variable is called the independent variable.
Here the distance the football covers in the presence and absence of wind is studied. So, the presence or absence of wind is the independent variable.
What is the wave velocity if the wave length is 100 cm and the frequency is 2 Hz?
Answer:
velocity = 2m/s
using v=fΠ
convert 100 CM to m
Answer:
200 cm per second
Explanation:
The equation for wave velocity=wavelength x frequency, since the wavelength is 100 and the frequency is two, the equation would be 100 x 2, which equals 200. Therefore, the correct answer is 200 cm per second.
find the difference between the actual values of the two sixes in the number 6036
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
help? :(
A 9,300 kg. a railroad car traveling at a velocity of 15m/s strikes a second boxcar at rest. If the two cars stick together and move off with a velocity of 6m/s, what is the mass of the second car?
Answer:
m2 = 13950 [kg]
Explanation:
To solve this problem we must use the principle of conservation of linear momentum, which is defined as the product of mass by velocity, and can be determined by means of the following expression:
P = m*v
where:
P = lineal momentum [kg*m/s]
m = mass [kg]
v = velocity [m/s]
Now that momentum is conserved, we need to analyze the conditions before the collision and after the collision. In this way we must propose the following equation:
ΣPbefore = ΣPafter
(m1*v1) + (m2*v2) = (m1+m2)*v3
where:
m1 = mass of the railroad car = 9300 [kg]
v1 = velocity of the railroad car before the collision = 15 [m/s]
m2 = mass of the box car [kg]
v2 = velocity of the boxcar before the collision = 0 (the car is at rest)
(m1 + m2) = combined mass of the cars, they stick together after the collision [kg]
v3 = combined velocity of the cars after the collision = 6 [m/s]
(9300*15) + (m2*0) = (m1+m2)*6
139500 = (6*9300) + 6*m2
83700 = 6*m2
m2 = 13950 [kg]
The mass of the second railroad car which was initially at rest is 13950kg.
Given the data in the question;
Mass of railroad car1; [tex]m_1 = 9300kg[/tex]Initial velocity of railroad car1; [tex]u_1 = 15m/s[/tex]Mass of railroad car2; [tex]m_2 = \ ?[/tex]
Since railroad car2 was initially at rest,
Initial velocity of railroad car1; [tex]u_2 = 0[/tex]After the strike, the wo cars stick together and moved
Final velocity of both railroad car1 and 2; [tex]v = 6m/s[/tex]To determine the mass of the second railroad car, we use conservation of linear momentum:
[tex]m_1u_1 + m_2u_2 = (m_1 + m_2 )v[/tex]
We substitute our given values into the equation
[tex](9300kg * 15m/s) + ( m_2 * 0 ) = ( 9300kg + m_2 )6m/s\\\\9300kg * 15m/s = ( 9300kg + m_2 )6m/s\\\\139500kg.m/s = 55800kg.m/s + ( m_2 * 6m/s )\\\\139500kg.m/s - 55800kg.m/s = m_2 * 6m/s\\\\83700kg.m/s = m_2 * 6m/s\\\\m_2 = \frac{83700kg.m/s}{6m/s} \\\\m_2 = 13950kg[/tex]
Therefore, the mass of the second railroad car which was initially at rest is 13950kg.
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how does a meteor transfer energy?
Answer:
Hope this answered your question!~ (Sorry if you get it wrong or I got it wrong-)
Explanation:
When an impact event happens, the enormous kinetic energy of the asteroid or meteorite – a massive body travelling at high speed – is partly transferred to the Earth but largely converted into heat and sound, creating pressure waves travelling radially outwards from its centre, similar to that of an atom bomb.
~The Confuzzeled homan
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:
2. True or false. As a wave travels through a given material its velocity changes.
Answer:
the answer is false
Explanation:
A wave travels at a constant velocity through a given material.
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
tony walks at an average speed of 70m/min from home to school. If the difference between his home and the school is 2100 m, how much time does it take for Tony to walk to school?
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:
Is nitrogen a compound
Answer:
Nitrogen gas (N2) is a molecule because the bond between the nitrogen atoms is a molecular bond. Water (H2O) is a molecular compound because it is a substance made from more than one kind of element that is held together with molecular bonds
Explanation:
One Newton equals .225
Study the motion map shown. Some of the vectors have been circled. A long black arrow pointing right labeled x. Above that are 5 green arrows of the same length pointing right, positioned end to end. Next to these are 2 shorter green arrows, each with small yellow arrows pointing left just above that are circled. Farther up from the line is a point. Much farther above that are 3 green arrows each longer than the previous. Above the green arrows are 3 yellow arrows of equal length pointed left, each circled. What do the circled vectors represent? distance speed velocity acceleration
Answer:
The object starts away from the origin and then moves toward the origin at a constant velocity. Next, it stops for one second. Finally, it moves away from the origin at a greater constant velocity.
Explanation:
Sample Response: The object starts away from the origin and then moves toward the origin at a constant velocity. Next, it stops for one second. Finally, it moves away from the origin at a greater constant velocity.
What did you include in your description? Check all that apply.
The object starts away from the origin.
The object moves toward the origin at a constant velocity.
The object stops for one second.
The object moves away from the origin at a greater constant velocity.
The circled vectors represent speed.
What is speed?
The is the ratio of distance traveled to time of motion. Speed is a scalar quantity because it has only only magnitude.
From the map, as the magnitude (size) of the green arrows changes, the size of the circled arrows changes accordingly.
Also, the direction of the circled arrow was constant for both top and bottom arrows.
Velocity changes with direction BUT speed does not change with direction, and has a complete meaning with only magnitude.
Thus, the circled vectors represent speed.
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what is induced current
Answer:
tu sala chutiya hai madarchod haramiA 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:)