Answer:
20m in 2 secs
Explanation:
t=2s
s=20m
hence the maximum height reached by stone is 20m in 2 s
An open winding in an electric motor means that ____. A. a wire in a winding is broken B. the centrifugal switch to the start winding is open C. the winding is making contact with the motor frame D. one winding is making contact with another winding
Answer:
A. a wire in a winding is broken.
Explanation:
An electric circuit can be defined as an interconnection of electrical components which creates a path for the flow of electric charge (electrons) due to a driving voltage.
Generally, an electric circuit consists of electrical components such as resistors, capacitors, battery, transistors, switches, inductors, etc.
Basically, an electric circuit is considered to be open when there's a broken continuity (broken path), which causes no current to flow through the circuit.
On the other hand, a closed circuit is one in which there's a flow of current due to a complete electrical path.
On a related note, an open winding in an electric motor means that a wire in a winding is broken.
If 200 ml of tea at 90 °C is poured into a 400 g glass cup initially at 25 °C, what would be the final temperature of the mixture?
Note: The specific heat capacity of water is 4186 J/kg °C, and the specific heat capacity of glass is 840 J/kg °C.
The final temperature of the mixture is 43.62 °C, If 200 ml of tea at 90 °C is poured into a 400 g glass cup initially at 25 °C.
To solve the question above, we apply the law of calorimetry
The law of calorimetry: which states that if there is no lost of heat the surrounding, heat lost is equal to heat gained, or it can be stated as heat absorbed by a cold body is equal to heat released by a hot body, provided there is no lost of heat to the surrounding.
The law above is expressed mathematically as
[tex]Cm(T-t) = C'm'(t-T')[/tex]............. Equation 1
Using equation 1 to solve the question,
Let: C = specific heat capacity of glass cup, m = mass of glass cup, C' = specific heat capacity of tea, m' = mass of tea, T = initial temperature of tea, T' = initial temperature of glass cup, t = final temperature of the mixture.From the question,Given: m = 400 g = 0.4 kg, C = 840 J/kg°C, m' = 200g (tea is a liquid made of water and the volume of water in ml is thesame a its mass in gram) = 0.2 kg, C' = 4186 J/kg.°C, T = 90°C, T' = 25°CSubstitute these values into equation 1 and solve for t₃[tex]0.4(840)(90-t) = 0.2(4186)(t-25)[/tex]
[tex]336(90-t) = 837.2(t-25)[/tex]
[tex]30240-336t = 837.2t-20930[/tex]
collect like terms
[tex]837.2t + 336t = 30240+20930[/tex]
[tex]1173.2t = 51170[/tex]
[tex]t = 51170/1173.2[/tex]
[tex]t = 43.62[/tex] °C
Hence, the final temperature of the mixture is 43.62 °C
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Answer:
The final temperature of the system is 41.657 °C.
Explanation:
Let consider the tea-cup system as an isolated system, that is, a system with no energy and mass interactions with the surroundings. From the perspective of the First Law of Thermodynamics, the tea releases heat, which is received by the glass cup until thermal equilibrium is reached. The following formula represents the model under assumption that process was at steady state:
[tex]\rho_{w}\cdot V\cdot c_{w}\cdot (T_{w,o}-T) + m_{g}\cdot c_{g}\cdot (T_{g,o}-T) = 0[/tex] (1)
Where:
[tex]\rho_{w}[/tex] - Density of water, in grams per mililiter.
[tex]V[/tex] - Volume of tea, in mililiters.
[tex]c_{w}[/tex] - Specific heat of water, in joules per gram-degree Celsius.
[tex]m_{g}[/tex] - Mass of the glass cup, in kilograms.
[tex]c_{g}[/tex] - Specific heat of the glass cup, in joules per gram-degree Celsius.
[tex]T_{w,o}[/tex] - Initial temperature of tea, in degrees Celsius.
[tex]T_{g,o}[/tex] - Initial temperature of the glass cup, in degrees Celsius.
[tex]T[/tex] - Final temperature of the tea-cup system, in degrees Celsius.
If we know that [tex]\rho_{w} = 1\,\frac{g}{mL}[/tex], [tex]V = 200\,mL[/tex], [tex]c_{w} = 4.186\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]m_{g} = 400\,g[/tex], [tex]c_{g} = 0.840\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]T_{w,o} = 90\,^{\circ}C[/tex] and [tex]T_{g,o} = 25\,^{\circ}C[/tex], then the final temperature of the tea-cup system is:
[tex]\rho_{w}\cdot V\cdot c_{w}\cdot (T_{w,o}-T) + m_{g}\cdot c_{g}\cdot (T_{g,o}-T) = 0[/tex]
[tex]\rho_{w}\cdot V\cdot c_{w}\cdot T_{w,o} +m_{g}\cdot c_{g}\cdot T_{g,o} - (\rho_{w}\cdot V\cdot c_{w}+m_{g}\cdot c_{g})\cdot T = 0[/tex]
[tex]T = \frac{\rho_{w}\cdot c_{w}\cdot T_{w,o}+m_{g}\cdot c_{g}\cdot T_{g,o}}{\rho_{w}\cdot V\cdot c_{w}+m_{g}\cdot c_{g}}[/tex]
[tex]T = \frac{\left(1\,\frac{g}{mL} \right)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (200\,mL)\cdot (90\,^{\circ}C)+(400\,g)\cdot \left(0.840\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (25\,^{\circ}C)}{\left(1\,\frac{g}{mL} \right)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (200\,mL) +(400\,g)\cdot \left(0.840\,\frac{J}{g\cdot ^{\circ}C} \right)}[/tex]
[tex]T = 41.657\,^{\circ}C[/tex]
The final temperature of the system is 41.657 °C.
Which of the following is a contact force?
A. applied
B. electromagnetic
C. nuclear
D. gravity
applied force is a contact force
6x+8=32 kết quả x là bao nhiêu
Answer:
6x+8=32
6x=32-8
6x=24
x=24:6
x= 4
vậy, x =4
How can we drop eggs the fewest amount of times without breaking it?
Answer:
drop in water
Explanation:
follow me m mm m
What is conserved in a thermodynamically closed system?
A. Both energy nor matter
B. Energy
C. Both energy and matter
D. Matter
Explanation:
C. Both energy and matter
please ans both urgent
Answer:
d I guess not sure
b if down I guess
Explanation:
if worng then plz dont say anything as I am not sure about the ans
Q- Wheel of a running vehicle has which energy?
(a) Vibrational Kinetic energy
(b) Translational Kinetic energy
(c) Rotational Kinetic energy
(d) All of the above
Answer:
Rotational kinetic energy
Explanation:
It is caused by circular motion.
A train 90m long stops in a train station with its front buffers in line with a lamp post on the platform. Later it starts off with an average acceleration of 0.45m/s. What will be its speed in kilometers per hour when the tail buffers pass the lamp post P?
Answer:
The speed of the train when the tail buffers pass the lamp post is 9 m/s
Explanation:
The given parameters are;
The length of the train = 90 m
The initial velocity of the train, u = 0
The average acceleration of the train, a = 0.45 m/s²
When the tail buffer pass the lamp post, P, we have;
The distance travelled, s = The length of the train = 90 m
The kinematic equation of motion is given as follows;
v² = u² + 2·a·s
Where;
v = The speed of the train when the tail buffers pass the lamp post
∴ v² = 0² + 2 × 0.45 m/s² × 90 m = 81 m²/s²
Therefore;
v = √(81 m²/s²) = 9 m/s
The speed of the train when the tail buffers pass the lamp post, v = 9 m/s.
Người ta thực hiện công 100J để nén khí trong một xilanh. Biết khí truyền ra xung quanh là nhiệt lượng 20J. Độ biến thiên nội năng của khí là
Answer:
DU = -80 Joules
Explanation:
Given the following data;
Work done = 100 J
Quantity of heat = 20 J
To find change in internal energy of the gas;
Mathematically, the change in internal energy of a system is given by the formula;
DU = Q - W
Where;
DU is the change in internal energy.
Q is the quantity of energy.
W is the work done.
Substituting the values into the formula, we have;
DU = 20 - 100
DU = -80 Joules
Therefore, the final energy of the gas is lower than its initial energy.
A bullet with a mass mb=13.5 g is fired into a block of wood at velocity vb=245 m/s. The block is attached to a spring that has a spring constant k of 205 N/m. The block and bullet continue to move, compressing the spring by 35.0 cm before the whole system momentarily comes to a stop. Assuming that the surface on which the block is resting is frictionless, determine the mass mw of the wooden block.
Momentum is conserved, so the sum of the momenta of the bullet and block before collision is equal to the momentum of the combined bullet-block system,
[tex]m_bv_b+m_wv_w = (m_b+m_w)v[/tex]
where v is the speed of the bullet-block system. The block starts at rest so it has no initial momentum, and solving for v gives
[tex]v = \dfrac{m_b}{m_b+m_w} v_b[/tex]
The total work W performed by the spring on the bullet-block system as it is compressed a distance x is
[tex]W = -\dfrac12kx^2[/tex]
where k is the spring constant, and the work done is negative because the restoring force of the spring opposes the bullet-block as it compresses the spring.
By the work-energy theorem, the total work done is equal to the change in the bullet-block's kinetic energy ∆K, so we have
[tex]W_{\rm total} = W = \Delta K[/tex]
The bullet-block starts moving with velocity v found earlier and comes to a stop as the spring slows it down, so we have
[tex]-\dfrac12kx^2 = -\dfrac12(m_b+m_w)v^2 \implies kx^2 = \dfrac{{m_b}^2}{m_b+m_w}{v_b}^2[/tex]
Solve for [tex]m_w[/tex]:
[tex]m_w=\dfrac1k\left(\dfrac{m_bv_b}x\right)^2-m_b[/tex]
[tex]m_w=\dfrac1{205\frac{\rm N}{\rm m}}\left(\dfrac{(0.0135\,\mathrm{kg})\left(245\frac{\rm m}{\rm s}\right)}{0.350\,\rm m}\right)^2-0.0135\,\mathrm{kg}\approx \boxed{0.422\,\mathrm{kg}}[/tex]
Provide two positives and two negatives the Sarah‘s family would face if they switched to organic farming
Answer:
Organic farming would have higher costs, and would be more complex than conventional farming. However, the Suarez family could charge a higher price for organic produce. This type of farming also would be better for the land.
Explanation:
Answer expert verified for the same question. (question/4178423)
Derive the following equations. :a=u-v by t
Describe the responses of the human ear to sound waves coming from the
right side, left side, or in phase.
If the sound comes from the right side, the waves reach the right ear before the left ear. if the sound comes from the left side, the waves reach the left ear before the right ear. The difference between the phases of waves reaching both ears is detected by the ears and then interpreted by the brain
Un muelle se alarga 20 cm cuando ejercemos sobre él una fuerza de 24 N. Calcula:El valor de la constante elástica del muelle
Answer:
120 Nm-1
Explanation:
Según la ley de Hooke;
F = Ke
F = fuerza sobre el resorte
K = constante de fuerza
e = extensión
Por eso;
K = F / e
K = 24N / 20 × 10 ^ -2m
K = 120 Nm-1
Straight wire of indefinite length (transient) passed by an electric current of 5.0 A. The magnetic field generated around this conductor at point M is 50 μT. Thus the distance from the conductor to point M is:
A. 2π cm
B. 0.2π cm
C. 2.0 cm
D. 0.20 cm
Answer:
C. 2.0 cm
Explanation:
The magnetic field around the wire at point M is given by Biot-Savart Law:
[tex]B = \frac{\mu_o I}{2\pi R}[/tex]
where,
B = Magnetic field = 50 μT = 5 x 10⁻⁵ T
I = current = 5 A
μ₀ = permeability of free space = 4π x 10⁻⁷ N/A²
R = distance of point M from wire = ?
Therefore,
[tex]5\ x\ 10^{-5}\ T = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(5\ A)}{2\pi R}\\\\R = \frac{(2\ x\ 10^{-7}\ N/A^2)(5\ A)}{5\ x\ 10^{-5}\ T}\\[/tex]
R = 0.02 m = 2 cm
Hence, the correct option is:
C. 2.0 cm
A uniform bridge span of weight 1200 kN and of
length 17.0 m rests on a support of width 1.0 m at
either end. A stationary lorry of weight 60 kN is the
only object on the bridge. Its centre of mass is 3.0m
from the centre of the bridge.
15.0 m
How do you format short quotations in an MLA-style document?
Answer:
To indicate short quotations (four typed lines or fewer of prose or three lines of verse) in your text, enclose the quotation within double quotation marks.
Một dây nhôm dài 10 m khi ở 25 độ C. Biết khi nhiệt độ tăng thêm 1 độ C thì chiều dài 1m dây nhôm sẽ tăng thêm 0,024mm.
a) Tính ăng chiều dài của 1m dây nhom khi nhiệt độ tăn thêm 75 độ C
b) Tính chiều dài dây nhôm ở 75 độ C
Answer:
??????? what language is this. um A then
8. What type(s) of motion do the particles in a solid undergo? A. vibrational, rotational, and translational B. vibrational and rotational C. vibrational only D. rotational only
Explanation:
Particles in solids are always vibrating (moving back and forth) in place.
help with this physics question please :)
Answer:
is that rm in you profile pic
pls someone help me pls…. and pls explain to me how
Answer:
1.12 × 10⁴ m/s
Explanation:
The escape velocity of the object v = √(2GM/R) where G = gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of the Earth = 6 × 10²⁴ kg and R = radius of the Earth = 6.4 × 10⁶ m
Since v = √(2GM/R)
Substituting the values of the variables into the equation, we have
v = √(2GM/R)
v = √(2 × 6.67 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)
v = √(13.34 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)
v = √(80.04 × 10⁻¹¹ × 10²⁴Nm²/kg/6.4 × 10⁶ m)
v = √(80.04 × 10¹³Nm²/kg ÷ 6.4 × 10⁶ m)
v = √(80.04 ÷ 6.4 × 10¹³ ÷ 10⁶Nm/kg)
v = √(12.50625 × 10⁷ Nm/kg)
v = √(125.0625 × 10⁶ Nm/kg)
v = 11.18 × 10³ m/s
v = 1.118 × 10 × 10³ m/s
v = 1.118 × 10⁴ m/s
v ≅ 1.12 × 10⁴ m/s
A 45.0 kg student runs at a constant velocity up the incline 6 metres high. If the power output of the student is 1.50 x 103 W, how long does it take the student to run the 9.0 m along the incline?
Answer:
The time taken is 1.76 s.
Explanation:
mass of student, m = 45 kg
height, h = 6 m
power, P = 1500 W
Power is defined as the rate of doing work.
Work done in moving height is
W = m g h
Let the time is t.
P = m g h / t
1500 = 45 x 9.8 x 6 / t
t = 1.76 s
help me with this one
Answer:
Explanation:
2. a
3. c
In a Rutherford scattering experiment, alpha parti- cles having kinetic energy of 7.70 MeV are fired toward a gold nucleus that remains at rest during the collision. The alpha particles come as close as 29.5 fm to the gold nucleus before turning around. (a) Calculate the de Broglie wave- length for the 7.70-MeV alpha particle and compare it with the distance of closest approach, 29.5 fm. (b) Based on this comparison, why is it proper to treat the alpha particle as a particle and not as a wave in the Rutherford scattering experiment
(a) The de Broglie wavelength is approximately 5.175 × 10⁻¹⁵ meters. The wavelength is lesser than the distance of closest approach
(b) It is proper to treat the alpha particle as a particle and not as wave because the distance of closest approach is much larger than and not comparable to its wavelength for the alpha particle for the alpha particle to be treated as a wave
The given parameters are;
The kinetic energy of the alpha particles = 7.70 MeV = 1.23368 × 10⁻¹² J
The distance from the gold nucleus the alpha particles reach = 29.5 fm
(a) The de Broglie wavelength of a particle is given as follows;
[tex]\mathbf{\lambda = \dfrac{h}{p}}[/tex]
Where;
λ = The wavelength
h = Planck's constant = 6.62607004 × 10⁻³⁴ m²·kg/s
p = The momentum of the particle = Mass of an electron, m × Velocity, v
The mass of an alpha particle, m ≈ 6.645 × 10⁻²⁷ kg
Therefore;
[tex]\lambda = \dfrac{h}{m \times v}[/tex]
The kinetic energy of the alpha particle, K.E. = (1/2)·m·v²
∴ v = √(2 × K.E./m)
Therefore;
[tex]\lambda = \dfrac{h}{m \times \sqrt{2 \times \dfrac{K.E.}{m} } } = \dfrac{h}{ \sqrt{2 \times m \times K.E.} }[/tex]
Plugging in the values of the variables gives;
[tex]\lambda = \dfrac{6.62607004 \times 10 ^{-34} }{ \sqrt{2 \times 6.645 \times 10 ^{-27} \times 1.23368 \times 10^{-12} } } \approx 5.175 \times 10^{-15}[/tex]
The de Broglie wavelength of the alpha particle, λ ≈ 5.175 × 10⁻¹⁵ m
The distance of closest approach = 29.5 fm = 29.5 × 10⁻¹⁵ m
Compared to the distance of closest approach, the wavelength of the alpha particle is lesser than the distance of closest approach
(b) Given that the distance of closest approach is six times larger than the wavelength of the alpha particle, and alpha particle behaving as waves are expected to approach closer to the gold nucleus in the region of their wavelength before deflection, therefore, the larger distance of closest approach is indicative of a charged particle to charged particle interaction, and therefore, particle behavior of alpha particles.
Learn more about de Broglie wavelength, particles and wave behavior of radiation here;
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express in standard form
(I)0.000038
Answer:
3.8 x 10^-5
Explanation:
all you doing is putting it in the standard form I hope this help
Explanation of the physics involved i the northern lights(aurora borealis) why can't it occur in mire southerns latitudes?
Answer:
The northern lights come from the interaction of electrically charged particles given off by the Sun surface during solar storms and the Earth's magnetic field which is pointed in the northern to southern poles of the Earth. Therefore, the charged particles that travel through millions of miles from the Sun to the Earth accelerate towards the magnetic poles and appear as the northern (and southern) lights
Boreal is an adjective word for the north or northern regions. In the southern latitudes, in the southern hemisphere, the phenomenon is called aurora australis (australis is the adjective for 'of the south')
Explanation:
During which step of the scientific method does a scientist determine
whether the hypothesis was supported?
A. Perform the experiment
B. Collect data
C. Draw conclusions
D. Design an experiment
SUBMN
PREVIOUS
Answer:
A
in performing the experiment the hypothesis is proved wrong or correct prediction , meaning of prediction is guessing,
hypothesis the second stage of scientific method , scientist predict or guess the answer to the problem ,
Experiment the third stage of scientific method
scientist examine the ways
"Perform the experiment" is the step of the scientific method where a scientist determines whether the hypothesis was supported.
What step of the scientific method is used to prove if the hypothesis is accepted or rejected?In the scientific method, experiments (often with controls and variables) are devised to test hypotheses. In the scientific method, analysis of the results of an experiment will lead to the hypothesis being accepted or rejected.
How do scientists determine whether a hypothesis is correct?The basic idea of a hypothesis is that there is no predetermined outcome. For a solution to be termed a scientific hypothesis, it has to be an idea that can be supported or refuted through carefully crafted experimentation or observation.
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a teacher and two students are mesuring the speed of sound. the teacher makes loud sound by hitting two cymbals together. each students starts a stopwatch then they see the teacher hit the cymbals, they each stop their stop watch when they hear the sound. describe how a sound wave moves through the air.
Answer:
Slowly and smoothly lol
Answer:
S.I. on Rs. 1600 = T.D. on Rs. 1680. Rs. 1600 is the P.W. of Rs. 1680, i.e., Rs. 80 is on Rs. 1600 at 15%. Time =100 x 80year=1year = 4 months.1600 x 153
Explanation:
Is this you are?
The gravitational force of the two objects is 6.67x10-11N. Explain this statement.
Answer:
it means that the force of attraction between two object in gravitation is 6.67×10-11N
It means that the force of attraction between two object in gravitation is 6.67×10-11N.
What is the formula of mass in gravitational force?The formula is g = GM/r2, Where M is the mass of the Earth, r is the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant. G (without the subscripts) is the gravitational constant, and c is the speed of light.
What is the gravitational force between two objects?The gravitational force between two objects is proportional to their masses and inversely proportional to the square of the distance between their centers. joining the two centers of masses.
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