i believe it would be Star A since Point A is a dwarf star and dwarf stars are usually most likely to have red coloring
Answer:
Star A
Explanation:
Literally the question has provided the answer itself
Calculation not required.
See the wordings
First star is dwarf star .
Dwarf star is mostly reddish brown or red colored .
Hence star A is the answer
The number of windings on the primary coil of a transformer
is 1.5 times greater than on the secondary coil. The primary
coil has a current of 3.0 A and a voltage of 12.0 V. Determine
the voltage and current on the secondary coil.
Answer:
I. Vs = 8.0 Volts.
II. Is = 4.5 Amperes.
Explanation:
Given the following data;
Np = 1.5Ns = [tex] \frac {N_{P}}{N_{S}} = 1.5 [/tex] ..... equation 1
Ip = 3.0 A
Vp = 12 V
To find the voltage and current on the secondary coil;
I. For the voltage in the secondary coil (Vs), we would use the following formula;
[tex] \frac {V_{P}}{V_{S}} = \frac {N_{P}}{N_{S}} [/tex] ...... equation 2.
Substituting eqn 1 into eqn 2, we have;
[tex] \frac {V_{P}}{V_{S}} = 1.5 [/tex]
[tex] \frac {12}{V_{S}} = 1.5 [/tex]
Cross-multiplying, we have;
[tex] V_{S} * 1.5 = 12 [/tex]
[tex] V_{S} = \frac {12}{1.5} [/tex]
Vs = 8.0 V
II. For the current in the secondary coil (Is), we would use the following formula;
[tex] \frac {I_{S}}{I_{P}} = \frac {N_{P}}{N_{S}} [/tex] .... equation 3
Substituting eqn 1 into eqn 3, we have;
[tex] \frac {I_{S}}{I_{P}} = 1.5 [/tex]
[tex] \frac {I_{S}}{3.0} = 1.5 [/tex]
Cross-multiplying, we have;
[tex] I_{S} = 1.5 * 3.0 [/tex]
Is = 4.5 A
Why aren’t magazine photos a good representation of what a healthy person looks like
: Chuyển động Một vật xuất phát từ A chuyển động đều về B cách A 240 m với vận tốc 10 m/s. Cùng lúc đó, một vật khác chuyển động đều từ B về A. Sau 15 s hai vật gặp nhau. Tìm vận tốc của vật thứ hai và vị trí hai vật gặp nhau.
A washing machine heats 10kg of water in each wash cycle. How much energy is saved by washing at 30'c instead of 50'c if the starting temperature of the cold water is 16'c? The specific heat capacity of water is 4200 J/Kg'c
Answer:
[tex]8.4 \times 10^{5}\; \rm J[/tex], assuming that there's no heat exchange between the washing machine and the environment.
Explanation:
Let [tex]m[/tex] denote the mass of water and [tex]c[/tex] the specific heat capacity of water. The energy required to raise the temperature of that much water by [tex]\Delta T[/tex] would be:
[tex]Q = c \cdot m \cdot \Delta T[/tex].
Washing at [tex]30\; \rm ^{\circ} C[/tex] would require a temperature change of [tex]\Delta T = 30\; \rm ^{\circ} C - 16\; ^{\circ} \rm C = 14\; \rm K[/tex].
Washing at [tex]50\; \rm ^{\circ} C[/tex] would require a temperature change of [tex]\Delta T = 50\; \rm ^{\circ} C - 16\; ^{\circ} \rm C = 34\; \rm K[/tex].
In both situations, [tex]c = 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1}[/tex] while [tex]m = 10\; \rm kg[/tex].
Calculate the energy required in either situation:
Washing at [tex]30\; \rm ^{\circ} C[/tex]:
[tex]\begin{aligned}& Q({30\; ^{\circ} {\rm C}}) \\ &= c \cdot m \cdot \Delta T \\ &= 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1} \times 10\; \rm kg \times 14\; \rm K \\ &= 588000 \times 10^{5}\; \rm J\end{aligned}[/tex].
Washing at [tex]50\; ^{\circ} {\rm C}[/tex]:
[tex]\begin{aligned}& Q({50\; ^{\circ} {\rm C}}) \\ &= c \cdot m \cdot \Delta T \\ &= 4.2 \times 10^{3}\; \rm J \cdot kg \cdot K^{-1} \times 10\; \rm kg \times 34\; \rm K \\ &= 1428000 \; \rm J\end{aligned}[/tex].
[tex]1428000\; \rm J - 588000\; \rm J = 8.4 \times 10^{5}\; \rm J[/tex].
Find A and effective resistance.
(Ill give Brainliest if you provide explaination)
Answer:
A = 2.4 A
[tex]R_{eq} = 5 \ \Omega[/tex]
Explanation:
The voltage in the circuit, V = 12 V
The given circuit shows four resistors with R₁ and R₂ arranged in series with both in parallel to R₃ and R₄ which are is series to each other
R₁ = 4 Ω
R₂ = 6 Ω
R₄ = 5 Ω
The voltage across R₃ = 6 V
Voltage across parallel resistors are equal, therefore;
The total voltage across R₃ and R₄ = 12 V
The total voltage across R₁ and R₂ = 12 V
The voltage across R₃ + The voltage across R₄ = 12 V
∴ The voltage across R₄ = 12 V - 6 V = 6 V
The current flowing through R₄ = 6V/(5 Ω) = 1.2 A
The current flowing through R₃ = The current flowing through R₄ = 1.2 A
The resistor, R₃ = 6 V/1.2 A = 5 Ω
Therefore, we have;
The sum of resistors in series are R₁ + R₂ and R₃ + R₄, which gives;
[tex]R_{series \, 1}[/tex] = R₁ + R₂ = 4 Ω + 6 Ω = 10 Ω
[tex]R_{series \, 2}[/tex] = R₃ + R₄ = 5 Ω + 5 Ω = 10 Ω
The sum of the resistors in parallel is given as follows;
[tex]\dfrac{1}{R_{eq}} = \dfrac{1}{R_{series \, 1}} + \dfrac{1}{R_{series \, 2}} = \dfrac{R_{series \, 2} + R_{series \, 1}}{R_{series \, 1} \times R_{series \, 2}}[/tex]
Therefore;
[tex]R_{eq} = \dfrac{R_{series \, 1} \times R_{series \, 2}}{R_{series \, 1} + R_{series \, 2}}[/tex]
Therefore;
[tex]R_{eq} = \dfrac{10\times 10}{10 + 10} \ \Omega = 5 \ \Omega[/tex]
[tex]R_{eq} = 5 \ \Omega[/tex]
The value of the current, A, in the circuit, I = V/[tex]R_{eq}[/tex]
A = I = 12 V/(5 Ω) = 2.4 A
A = 2.4 A
An electromagnetic wave has a frequency of 6.0 x 10^18 Hz. What is the
wavelength of the wave? Use the equation 2 = and the speed of light as 3.0
x 108 m/s.
Answer:
Wavelength = 5 * 10^{-11} meters
Explanation:
Given the following data;
Frequency = 6.0 x 10^18 Hz
Speed = 3 * 10⁸ m/s
To find the wavelength of the wave;
Mathematically, the wavelength of a wave is given by the formula;
[tex] Wavelength = \frac {speed}{frequency} [/tex]
Substituting into the formula, we have;
[tex] Wavelength = \frac {3 * 10^{8}}{6.0 x 10^{18}} [/tex]
Wavelength = 5 * 10^{-11} meters
What evidence is there that the use of fossil fuels, which produce carbon dioxide, is causing climate change?
Answer:
The carbon dioxide produced by fossil fuel into the air is a greenhouse gas just as is nitrous oxide, methane, water vapor, and synthetic gases that contain fluorine. Compared to the other greenhouse gases, carbon dioxide is the most abundantly present greenhouse gas.
The greenhouse gases cause greenhouse effect which is the observed trapping of heat in the atmosphere, similar to the glass roof of a greenhouse, thereby causing the average global temperature to rise, and changing the climate through global warming
There is presently a 1°C rise in the average global temperature as part of the Earth reflected heat from the Sun is returned back to Earth by the increasing greenhouse gas presence in the atmosphere which cause the greenhouse effect
Explanation:
Answer:
The carbon dioxide produced by fossil fuels in the air is a greenhouse gas, as is nitrous oxide, methane, water vapor, and synthetic gases containing fluorine. Compared to the other greenhouse gases, carbon dioxide is the most abundant greenhouse gas.
The greenhouse gases cause the greenhouse effect which is the observed trapping of heat in the atmosphere, similar to the glass roof of a greenhouse, thereby causing the average global temperature to rise, and changing the climate through global warming
There is presently a 1°C rise in the average global temperature as part of the Earth's reflected heat from the Sun is returned to Earth by the increasing greenhouse gas presence in the atmosphere which causes the greenhouse effect
Explanation:
I got a 100% on this assignment copy it and put it on your notes then go sentence by sentence copy but dont highlight any "." you will not be able to paste it into the box add the "." after you paste it, it one sentence.
ONE SENTENCE AT A TIME NO ". ' or 1°" AT ALLA particle makes 800 revolution in 4 minutes of a circle of 5cm. Find
i. it's period
ii. Angular Velocity
iii. Linear Velocity
iv. It's acceleration
PLEASE FORMULAE SHOULD BE WRITTEN CLEARLY.
YOU CAN SNAP AND SEND
Answer:
i) The period of the particle is 0.3 seconds
ii) The angular velocity is approximately 20.94 rad/s
iii) The linear velocity is approximately 1.047 m/s
iv) The centripetal acceleration is approximately 6.98 m/s²
Explanation:
The given parameters are;
The number of revolution of the particle, n = 800 revolution
The time it takes the particle to make 800 revolutions = 4 minutes
The dimension of the circle = 5 cm = 0.05 m
Given that the dimension of the circle is the radius of the circle, we have;
i) The period of the particle, T = The time to complete one revolution
T = 1/(The number of revolutions per second)
∴ T = 1/(800 rev/(4 min × 60 s/min)) = 3/10 s
The period, T = 3/10 seconds = 0.3 seconds
ii) The angular velocity, ω = Angle covered/(Time)
800 revolutions in 4 minutes = Angle of (800 × 2·π) in 4 minutes
∴ ω = (800 × 2·π)/(4 × 60) = 20·π/3
The angular velocity, ω = 20·π/3 rad/s ≈ 20.94 rad/s
iii) The linear velocity, v = r × ω
∴ The linear velocity, v = 0.05 m × 20·π/3 rad/s = π/3 m/s ≈ 1.047 m/s
iv) The centripetal acceleration, [tex]a_c[/tex] = v²/r
∴ The centripetal acceleration, [tex]a_c[/tex] = (π/3)²/(0.05) = 20·π/9
The centripetal acceleration, [tex]a_c[/tex] = 20·π/9 m/s² ≈ 6.98 m/s²
Two football players run towards each other along a straight path in Penrith Park in the clash between the Melbourne storms and the Penrith Panthers a month ago. Melbourne's Justin Olam who is about 95kg and ran towards Viliame Kikau at 3.75m/s. Viliame Kikau is 111kg and moves towards Justin Olam at 4.10m/s. They end up in a head-on collision and are stuck together.
A) What is their velocity immediately after the collision?
B) What are the initial and final kinetic energies of the system?
Answer:
a) v = 0.4799 m / s, b) K₀ = 1600.92 J, K_f = 5.46 J
Explanation:
a) How the two players collide this is a momentum conservation exercise. Let's define a system formed by the two players, so that the forces during the collision are internal and also the system is isolated, so the moment is conserved.
Initial instant. Before the crash
p₀ = m v₁ + M v₂
where m = 95 kg and his velocity is v₁ = -3.75 m / s, the other player's data is M = 111 kg with velocity v₂ = 4.10 m / s, we have selected the direction of this player as positive
Final moment. After the crash
p_f = (m + M) v
as the system is isolated, the moment is preserved
p₀ = p_f
m v₁ + M v₂ = (m + M) v
v =[tex]\frac{m v_1 + M v_2}{m+M}[/tex]
let's calculate
v = [tex]\frac{ -95 \ 3.75 \ + 111 \ 4.10}{95+111}[/tex]
v = 0.4799 m / s
b) let's find the initial kinetic energy of the system
K₀ = ½ m v1 ^ 2 + ½ M v2 ^ 2
K₀ = ½ 95 3.75 ^ 2 + ½ 111 4.10 ^ 2
K₀ = 1600.92 J
the final kinetic energy
K_f = ½ (m + M) v ^ 2
k_f = ½ (95 + 111) 0.4799 ^ 2
K_f = 5.46 J
to all the physicians please help this is for my assignment
Answer:
Q. 1. Newton's Law of gravitation states that all bodies in the universe exerts a force of attraction on all other bodies in the universe with a proportional force to both the product of the masses of the bodies and inversely proportional to the square of the distance between their centers
Mathematically, we have;
[tex]F = G \times \dfrac{m_1 \times m_2}{R^2}[/tex]
Where;
m₁, and m₂ are the masses of the bodies
R = The distance between their centers
G = The gravitational constant = 6.6743 × 10⁻¹¹ N·m²/kg²
The gravitational constant, G, is the Newton's law of gravitation's constant of proportionality between the force of attraction that exist two bodies and the product of their masses divided by the square of the distance between their centers
Q. 2. Newton's law of gravitation in vector form is presented as follows;
[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12}[/tex]
The above equation gives the gravitational force of attraction of body 1 on body 2, with the negative sign and unit vector indicating that the force of of gravity is towards body 1
The force of gravity of body 2 on 1 is presented as follows;
[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{12}^2} \cdot \hat R_{21}[/tex]
The gravitational force of attraction of body 2 on body 1 is therefore, equal in magnitude and opposite in direction of the gravitational force of body 1 on body 2 (towards body 2)
[tex]-\underset{F_{12}}{\rightarrow} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot -(\hat R_{21}) = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21}[/tex]
[tex]-\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21} = \underset{F_{21}}{\rightarrow}[/tex]
[tex]-\underset{F_{12}}{\rightarrow} = \underset{F_{21}}{\rightarrow}[/tex]
Explanation:
A car has a mass of 2000 kg. While it is traveling along a perfectly flat road, it goes around an unbanked turn that has a radius of 40.0 m. The coefficient of static friction between the car tires and the road is 0.500. The car travels successfully around the turn at a constant speed of 10.0 m/s. Calculate the magnitude of the car's acceleration as it goes around the turn. _______ m/s^2
Answer:
2.5 m/s²
Explanation:
The given parameters are;
The mass of the car, m = 2,000 kg
The radius of the car, r = 40.0 m
The coefficient of friction between the car tires and the road, μ = 0.500
The constant speed with which the car moves, v = 10.0 m/s
The normal reaction of the road on the car, N = The weight of the car;
∴ N = m × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
N ≈ 2,000 kg × 9.81 m/s² = 19,620 N
The frictional force, [tex]F_f[/tex] = μ × N
The centripetal force, [tex]F_c[/tex] = m·v²/r
The car moves without slipping when [tex]F_f[/tex] = [tex]F_c[/tex]
Therefore, [tex]F_f[/tex] = 0.500 × 19,620 N = 2,000 kg × [tex]v_{max}[/tex]²/40.0 m
∴ [tex]v_{max}[/tex] = √(0.500 × 19,620 N × 40.0 m/2,000 kg) ≈ 14.007 m/s
Therefore, the velocity with which the car moves, v < [tex]v_{max}[/tex]
The cars centripetal acceleration, [tex]a_c[/tex] = v²/r
∴ [tex]a_c[/tex] = (10.0 m/s)²/40.0 m = 2.5 m/s²
The cars centripetal acceleration as it goes round the turn, [tex]a_c[/tex] = 2.5 m/s².
A jet airplane is in level flight. The mass of the airplane is m=8950 kg. The airplane travels at a constant speed around a circular path of radius R=9.33 mi and makes one revolution every T=0.123 h. Given that the lift force acts perpendicularly upward from the plane defined by the wings, what is the magnitude of the lift force acting on the airplane?
Answer:
The net force is 91780.8 N.
Explanation:
mass, m = 8950 kg
Radius, R = 9.33 miles = 15015.2 m
Time, T = 0.123 h = 442.8 s
There are two forces acting on the plane.
Horizontal force is the centripetal force and the vertical force is the weight.
[tex]Fx =m R w^2\\\\Fx = m R \frac{4\pi^2}{T^2}\\\\Fx = 8950\times 15015.2\times \frac{4\times 3.14\times 3.14}{442.8\times 442.8}\\\\Fx = 27030.8 N \\\\Fy = m g \\\\ Fy = 8950\times 9.8 \\\\Fy = 87710 N[/tex]
The net force is
[tex]F = \sqrt{Fx^2 + Fy^2}\\\\F = \sqrt {27030.8^2 + 87710^2}\\\\F = 91780.8 N[/tex]
Water has a specific heat of 4.186 J/g°C, and ethanol has a specific heat of 2.450 J/g°C. Based on this information, which best compares water and ethanol?
The question is incomplete, the complete question is;
Water has a specific heat of 4.186 J/g°C, and ethanol has a specific heat of 2.450 J/g°C. Based on this information, which best compares water and ethanol?
It requires more heat to raise the temperature of a gram of ethanol by 1°C.
There are more molecules in a gram of water.
Ethanol has a lower formula mass.
Water has more protons and neutrons in its nuclei.
Answer:
There are more molecules in a gram of water.
Explanation:
Let us recall that the molar mass of water is 18g/mol while the molar mass of ethanol is 46 g/mol.
Hence;
1 g of water contains 18 g
There are 6.02 × 10^23/18g = 3.34 × 10^22 molecules in 1 g of water
1 g of ethanol contains 46 g
There are 6.02 × 10^23/46 g = 1.31 ×10^22 molecules
Hence, there are more molecules in 1 g of water than in 1g of ethanol.
Answer:
there are more molecules in 1 g of water than in 1g of ethanol.
Explanation:
edge 23
Lifestyle practice that can improve your quality of life
Explanation:
And keep changing gradually.
Eat a variety of foods. ...
Base your diet on plenty of foods rich in carbohydrates. ...
Replace saturated with unsaturated fat. ...
Enjoy plenty of fruits and vegetables. ...
Reduce salt and sugar intake. ...
Eat regularly, control the portion size. ...
Drink plenty of fluids. ...
Maintain a healthy body weight
A car increase its speed steadily from 30km/hr to 60km/hr in 1 min A what is the average speed during this time
Explanation:
initial velocity(u)=30km/hr = 30*1000/60*60=8.33 m/s
final velocity(v) =60km/hr = 60*1000/60*60 =16.67 m/s
time taken(t) = 1 minutes
= 60 seconds
Now,
Average velocity = u+v/2
= 8.33 m/s + 16.67m/s÷2
=12.5 m/s
which statement accurately describes how the acceleration of an object in free fall changes
Answer:
A ball rolls off the table and free falls to the ground. Which statement accurately describes its acceleration? Its acceleration is downward but remains a constant value as it falls.
I let go of a piece of bread from a balcony. A bird flying 5.0 m overhead sees me drop it, and starts to dive straight down towards the bread the instant that I release it. She catches it after it falls 3.0 m. Assuming she accelerates constantly from rest (v0 = 0) at the time I let go of the bread, what is her acceleration? Show your work
This question can be solved using the equations of motion. There are two scenarios where the equations of motion can be used. The first scenario is the free-fall motion of the piece of bread. The second scenario is the uniformly accelerated motion of the bird.
The acceleration of the bird is "a = 26.13 m/s²".
First, we will calculate the time taken by the bread to fall 3 m. Using the second equation of motion for this free-fall motion:
[tex]h = v_it + \frac{1}{2}gt^2[/tex]
where,
h = height fall = 3 m
vi = initial velocity = 0 m/s
g = acceleration due to gravity = 9.8 m/s²
t = time taken = ?
Therefore,
[tex]3\ m = (0\ m/s)t+\frac{1}{2}(9.8\ m/s^2)t^2\\t = \sqrt{\frac{(3\ m)(2)}{9.8\ m/s^2}}\\\\t = 0.78\ s[/tex]
The bird took the same time to catch the bread. Now applying the second equation of motion to the bird's motion:
[tex]s = v_it + \frac{1}{2}at^2[/tex]
where,
s = distance covered by the bird = 5 m + 3 m = 8 m
vi = initial velocity of the bird = 0 m/s
a = acceleration of the bird = ?
t = time taken = 0.78 s
Therefore, using these values we get:
[tex]8\ m = (0\ m/s)(0.78\ s)+\frac{1}{2}a(0.78\ s)^2\\\\a = \frac{16\ m}{(0.78\ s)^2}[/tex]
a = 26.13 m/s²
Learn more about the equations of motion here:
https://brainly.com/question/24018491?referrer=searchResults
What do you mean by unit?
Unit is the quantity of a constant magnitude which is used to measure the magnitudes of other quantities of the same nature.
Answer:
The standard known quantity which is used to measure a physical quantities is known as unit.
A van of mass 1200kg is moving with speed of 90km/hr. It is brought in 3 seconds by applying brakes. Calculate the force applied to bring van to rest.
Answer:
Explanation:
The main equation to solve this is F = ma, where F is the force applied to the brakes with respect to its acceleration. We have the mass that we need, but we do not have the acceleration. That's the first thing we have to find. However, our velocity needs to be stated in m/s and right now it's in km/h. Converting that:
[tex]90\frac{km}{hr}*\frac{1000m}{1km}*\frac{1hr}{3600s} =25\frac{m}{s}[/tex] Now we're ready to find the acceleration:
[tex]a=\frac{v_f-v_0}{t}[/tex] where the top line there translates to the final velocity minus the initial velocity.
[tex]a=\frac{0-25}{3.0}[/tex] so the acceleration is -8.3 m/s/s
We can use that now in the force equation above:
F = 1200(-8.3) and
F = -1.0 × 10⁴ N (that's 10,000 N to the correct number of sig dig's; the negative sign means that the force is being applied in the direction opposite to that which the van is currently moving)
A person climbs out of swimming pool and stands in the open air.Explain why evaporation of water from the surface of the persons body causes the person to feel cold
Answer:
The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.
Thank You! Please mark me Brainliest!
The spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum. have wavelengths that are longer than normal. have a higher intensity in the red part of the spectrum. have wavelengths that are shorter than normal.
have a higher intensity in the red part of the spectrum
Because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum
Most galaxies' spectra have been redshifted, which means that their spectral lines are now pushed away from their normal or rest wavelengths and towards longer wavelengths. When an object travels away from an observer, the Doppler effect causes the shift phenomenon.
The Big Bang hypothesis and the concept of the expanding universe, show that galaxies are moving away from us, observed from the redshift lines.
The waves' apparent wavelengths shift as a result, changing the color of light waves or the pitch of sound waves.
Hence, because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum.
To learn more about the Doppler effect, here:
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An object is thrown from the ground with an initial velocity of 30 m/s. What is the velocity at the point 25 m above the ground?
Answer:
It's a pretty simple suvat linear projectile motion question, using the following equation and plugging in your values it's a pretty trivial calculation.
V^2=U^2+2*a*x
V=0 (as it is at max height)
U=30ms^-1 (initial speed)
a=-g /-9.8ms^-2 (as it is moving against gravity)
x is the variable you want to calculate (height)
0=30^2+2*(-9.8)*x
x=-30^2/2*-9.8
x=45.92m
Answer:
35
Explanation:
dfddffffffffffffdddfr
2) Define volume. Explain in detail how can volume of irregular object be determined?
PLZ HELP NEED THIS RN
The three dimensional space of a body is called volume
a sphere of diameter 6.0
cm is moulded into a thin wire of diameter 0.2 mm calculate the length of the wire in metres
Answer:
V1 = 4/3 pi R^3 = pi D^3 / 6 D = 2 R volume of sphere
V2 = pi r^2 L = pi d^2 L / 4 volume of wire
V2 / V1 = 1 = 3/2 d^2 L / D^3 since volumes are equal
L = 2/3 D^3 / d^2 = 2/3 * 6^3 / .02^2 = 360,00 cm = 3600 m
HELP ASAP!!!
What size object (impactor) may create such a crater?
Answer:
I HOPE IT WILL HELP YOU.
:D
The energy required to change the state of a substance was determined to be E(H).
If the mass of the substance was DOUBLED, the value of E(H) will
(A) be halved
(B) be doubled
(C) be quadrupled
(D) remain constant
Answer:
ccccccccc or bbbbbbb or aaaaaaaa or ddddddd
20 The metal surface of a kettle is hot. What happens to the cool air outside the kettle when it comes into contact with the hot kettle?
A The density of the air decreases and the air falls.
B The density of the air decreases and the air rises.
C The density of the air increases and the air falls.
D The density of the air increases and the air rises.
D. The density of the sir increases and the air rises.
When coming in contact with the kettle, it becomes hot, it expands and rises up, due to lesser density as compared to the surrounding air.
A object of mass 200kg is pushed from rest by a force of 500N along a horizontal plane for 5.0 seconds. Calculate the acceleration of the object
Answer:
force=mass×acceleration
hence
acceleration is given by force÷mass
(500÷200)*5=12.5
steel wire 8m long and 4mm in diameter is fixed to two rigid b. [1] supports. Calculate the increase in tension when the temperature falls by 10°C. Given linear expansivity of steel, a 12x10 %/K, Young's modulus for steel, Y = 2x10¹¹ N/m².
Answer:
301.6 N
Explanation:
The length of the wire L₀ = 8 m and its diameter, d = 4 mm = 4 × 10⁻³ m. Since its temperature drops by 10°C, it will have a change in length ΔL = L₀αΔθ where α = linear expansivity of steel, a 12 × 10⁻⁶ /K, and Δθ = temperature change = -10°C = -10 K(negative since it is a drop)
So, the strain, ε = ΔL/L₀ = αΔθ = 12 × 10⁻⁶ /K × 10 K = 12 × 10⁻⁵
Now the Young's modulus of steel, Y = σ/ε where σ = stress = T/A where T = increase in tension in steel wire and A = cross-sectional area of wire = πd²/4 where d = diameter of wire = 4 × 10⁻³ m and ε = strain = 12 × 10⁻⁵
So, σ = Yε
Since Y = 2 × 10¹¹ N/m².
Substituting the values of the variables into the equation, we have
σ = Yε
σ = 2 × 10¹¹ N/m² × 12 × 10⁻⁵
σ = 24 × 10⁶ N/m²
Since σ = T/A
T = σA
T = σπd²/4
Substituting the values of the variables into the equation, we have
T = σπd²/4
T = 24 × 10⁶ N/m² × π × (4 × 10⁻³ m)²/4
T = 24 × 10⁶ N/m² × π × 16 × 10⁻⁶ m²/4
T = 24 × 10⁶ N/m² × π × 4 × 10⁻⁶ m²
T = 96 N × π
T = 301.59 N
T ≅ 301.6 N
So, the increase in tension in the steel wire is 301.6 N
Highlight two factors which shows that heat from the sun does not reach the earth surface by convection
Answer:
Explanation:
The heat from the Sun gets to the surface of the Earth by radiation and not by convection because:
i. Radiation does not require material medium for its propagation: Since the space between the Sun and Earth is a vacuum ( i.e it is an empty space), then the only method for the heat from to Sun to get to the Earth is by radiation. This method does not require a material medium, while convection is a method that requires material medium for its propagation.
ii. Radiation occurs without heating the intervening medium: During the propagation of the heat from the Sun to the Earth, the space between the two heavenly bodies is not heated up. Some fraction of the heat after hitting the surface of the Earth get reflected back into the Earth's atmosphere. While in convection, the medium would have been heated up in the process.
