which best describes how air moves during convection?
a. cool air warms as it mixes with denser air
b. warm air cools as it mixes with cooler, denser air
c. warm air is displaced by cooler denser air
a. cool air warms as it mixes with denser air
Explanation:
c. warm air is displaced by cooler denser air
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Firing a small rocket that starts at rest, the VMS-2 rises vertically under uniform acceleration, and in 50 seconds all the fuel is burned out. What is the maximum height at which the rocket rises?
Es frecuente que en las instalaciones eléctricas domésticas se utilice alambre de cobre de 2.05 mm de diámetro. Determine la resistencia de un alambre de ese tipo con longitud de 24.0 m
Answer:
The resistance is 0.124 ohm.
Explanation:
It is common for domestic electrical installations to use copper wire with a diameter of 2.05 mm. Determine the resistance of such a wire with a length of 24.0 m.
diameter, d = 2.05 mm
radius, r = 1.025 mm
Length, L = 24 m
resistivity of copper = 1.7 x 10^-8 ohm m
Let the resistance is R.
[tex]R =\rho \frac{L}{A}\\\\R = \frac {1.7\times10^{-8}\times 24}{3.14\times1.025\times1.025\times 10^{-6}}\\\\R = 0.124 ohm[/tex]
Two people are pulling the same 12 kg box along a flat, frictionless surface. One
pulls up and to the right with a 30 N force at 20°, the second pulls up and to the left
with a 45 N force at 50°. What is the acceleration of the box?
3.00 m/s^2
09.80 m/s^2
O 1.474 m/s^2
0.474 m/s^2
Answer:
The acceleration is 0.062 m/s^2.
Explanation:
mass = 12 kg
F = 30 N at 20° right
F' = 45 N at 50° left
Let the acceleration is a.
The net force is
F'' = F' cos 50° - F cos 20°
F'' = 45 x 0.643 - 30 x 0.94 = 28.94 - 28.2 = 0.74 N
According to the Newton's second law
0.74 = 12 x a
a = 0.062 m/s^2
What would be the electric field (magnitude and direction) of 1.50 cm to the right of a charge of -6.5 × 10-6 C?
Answer:
Explanation:
The formula for the electric field is
[tex]E=\frac{kQ}{r^2}[/tex] where E is the magnitude of the electric field, k is Coulomb's constant, Q is the charge of the particle (which is NOT included in the formula), and r is the distance between the centers of the charges (for lack of a better description).
[tex]E=\frac{(9.0*10^9)*(6.5*10^{-6})}{(1.50)^2}[/tex] and we get, to 2 sig fig's
E = 2.6 × 10⁴ to the left (since electric fields are always pointing toward the negative charge and the electric field is to the right of the negative charge)
Deepta adhivnav having weight 450N and 350N are playing see-saw. Deepta sits at a distance of 2m from the fulcrum, how far should abhinav be seated in order to balance deepta?
Answer:
Explanation:
This is a torque problem where balance is achieved when the sum of the torques equal 0. The equation for torque is
[tex]\tau=F*r[/tex] where F is the force in Newtons that is perpendicular to the lever arm, and r is the length of the lever arm in meters.
450(2) = 350r and
[tex]\frac{450(2)}{350}=r[/tex] so
r = 2.6 m
Size of image is equal to size of object in convex lens, when object is placed:
(a) at F
(b) between F & O
(c) between F & 2F
(d) at 2F
Pls answer fast
Explanation:
the object should be placed at 2F
Answer:
at 2F
Explanation:
hope it will help you
Match each feature related to the process of seafloor spreading with its location on the diagram
Answer:
Seafloor spreading is a geological process that occurs in the ocean. It is occurs due to divergent plate tectonics. As, lithospheric plates of the ocean moves away from each other, the heat from the mantle liberates as convection currents that decreases the density of the crust. The less dense material rises, resulting the elevation of the seafloor, which is called as sea floor spreading.
Explanation:
Imagine a landing craft approaching the surface of Callisto, one of Jupiter's moons. If the engine provides an upward force (thrust) of 3456 N, the craft descends at constant speed; if the engine provides only 2333 N, the craft accelerates downward at 0.39 m/s2. What is the weight of the landing craft in the vicinity of Callisto's surface
Answer:
[tex]W=3456 N[/tex]
Explanation:
Force 1 [tex]F_1=3456[/tex]
Force 2 [tex]F_2=2333N[/tex]
Acceleration at stage 2 [tex]a_2=0.39[/tex]
Generally the weight of the Craft W is given as
W= upward force(thrust)
Therefore
[tex]W=3456 N[/tex]
A walkway suspended across a hotel lobby is supported at numerous points along its edges by a vertical cable above each point and a vertical column underneath. The steel cable is 1.27cm in diameter and is 5.75m long before loading. The aluminum column is a hollow cylinder with an inside diameter of 16.14cm, and an unloaded length of 3.25m. When the walkway exerts a loa force of 8500N on one of the support points, through what distance does the point move down?
Answer:
[tex]\triangle I=8.60*10^{-4}m[/tex]
Explanation:
From the question we are told that:
Diameter [tex]d=1.27cm[/tex]
Length [tex]l=5.75m[/tex]
Diameter of aluminum column [tex]d_a=16.14cm[/tex]
Length of aluminum column [tex]l_a=3.25m[/tex]
Load Force [tex]F=8500N[/tex]
Generally the equation for Young modulus is mathematically given by
[tex]\gamma=\frac{FL}{A \triangle L}[/tex]
Given the The load force
[tex]F=\frac{Y_aA_a\triangle I}{L_a}+\frac{YA \triangle I}{L}[/tex]
[tex]\triangle I=\frac{F}{\frac{Y_aA_a}{L_a}}+\frac{YA}{L}[/tex]
[tex]\triangle I=\frac{8500N}{ \frac{7*10^{10} \pi (0.1624^2-0.1614^2)}{4*3.15}+ \frac{20*10^10 \pi (0.0127^2)}{4(5.75)}}[/tex]
[tex]\triangle I=8.60*10^{-4}m[/tex]
slader At a carnival, you can try to ring a bell by striking a target with a 10.8-kg hammer. In response, a 0.408-kg metal piece is sent upward toward the bell, which is 4.23 m above. Suppose that 18.8 percent of the hammer's kinetic energy is used to do the work of sending the metal piece upward. How fast must the hammer be moving when it strikes the target so that the bell just barely rings
Answer:
The hammer must be moving at a speed of approximately 4.082 meters per second.
Explanation:
According to the statement and based on Principle of Energy Conservation, change in gravitational potential energy experimented by the metal piece ([tex]U_{g,o}[/tex]), in joules, must be equal to 18.8 percent of the translational kinetic energy of the hammer ([tex]K_{h}[/tex]), in joules.
[tex]U_{g, o} = 0.188\cdot K_{h}[/tex] (1)
By definitions of gravitational potential and translational kinetic energies, we expand (1):
[tex]m_{o}\cdot g\cdot h = 0.188\cdot \left(\frac{1}{2}\cdot m_{h}\cdot v^{2}\right)[/tex] (2)
Where:
[tex]m_{o}[/tex] - Mass of the metal piece, in kilograms.
[tex]g[/tex] - Gravitational acceleration, in meters per square second.
[tex]h[/tex] - Distance travelled by the metal piece, in meters.
[tex]m_{h}[/tex] - Mass of the hammer, in kilograms.
[tex]v[/tex] - Initial speed of the hammer, in meters per second.
If we know that [tex]m_{o} = 0.408\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]h = 4.23\,m[/tex] and [tex]m_{h} = 10.8\,kg[/tex], then the initial speed of the hammer is:
[tex]m_{o}\cdot g\cdot h = 0.188\cdot \left(\frac{1}{2}\cdot m_{h}\cdot v^{2}\right)[/tex]
[tex]10.638\cdot m_{o}\cdot g \cdot h = m_{h}\cdot v^{2}[/tex]
[tex]v = 3.261\cdot \sqrt{\frac {m_{o}\cdot g \cdot h}{m_{h}}}[/tex]
[tex]v = 3.261\cdot \sqrt{\frac{(0.408\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (4.23\,m)}{10.8\,kg} }[/tex]
[tex]v \approx 4.082\,\frac{m}{s}[/tex]
The hammer must be moving at a speed of approximately 4.082 meters per second.
What wave moves in the same direction as the force that created it?
1. Interference waves
2. Reflected waves
3. Transverse waves
4. Longitudinal waves
Answer:
im saying 4. its just a guess it makes sense tho
Explanation:
sorry for getting this wrong.
Answer:
longitudinal waves
Explanation:
I got it right
STATE THE LAWS OF CONSERVATION OF MOMENTUM
[tex]\Huge \mid \underline {\mathcal {{{\color{purple}{Answer...}}}}} \mid[/tex]
When two bodies collide with each other in the absence of an external force, then the total final momentum of the bodies is equal to their total initial momentum.
Which wave has the smallest amplitude?
Answer:
C. C
Explanation:
A wave can be defined as a disturbance in a medium that progressively transports energy from a source location to another location without the transportation of matter.
In Science, there are two (2) types of wave and these include;
I. Electromagnetic waves: it doesn't require a medium for its propagation and as such can travel through an empty space or vacuum. An example of an electromagnetic wave is light.
II. Mechanical waves: it requires a medium for its propagation and as such can't travel through an empty space or vacuum. An example of a mechanical wave is sound.
A crest can be defined as the highest (vertically) point on a waveform.
On a related note, a trough is the lowest (vertically) on a waveform.
An amplitude can be defined as a waveform that's measured from the center line (its origin or equilibrium position) to the bottom of a trough or top of a crest. Thus, the vertical axis (y-axis) is the amplitude of a waveform i.e it's measured vertically.
In this scenario, waveform C which is represented by a blue curvy line has the smallest amplitude in comparison with the other waveforms because it has the minimum height when measured from the origin.
In contrast, waveform A represented by a purple line has the highest amplitude because it has the maximum height when measured from the origin.
Mathematically, the amplitude of a wave is given by the formula;
x = Asin(ωt + ϕ)
Where;
x is displacement of the wave measured in meters.A is the amplitude.ω is the angular frequency measured in rad/s.t is the time period measured in seconds.ϕ is the phase angle.Answer:
The answer is indeed D as the comment above suggests.
Explanation:
Simply put, wave D's highest point is closer to the line than all of the other high points of A, B and C
What uses non-renewable energy?
A)a gematrical heating system
B)a nuclear power station
C)a solar panel
D)a wind turbine
I need help with this question below ASAP!
A net force of 400 N is exerted on an object. Its vector speed goes from 66 km / h to 30 km / h in 2.5 s. a) What is the acceleration of this object? B) What is its mass?
Thank you for your help :)
Answer:
Mass M = 100 kg
Explanation:
Given;
Net force = 400 N
Initial velocity u = 66 km/h
Final velocity v = 30 km / h
Time taken = 2.5second
Find:
Acceleration of this object a
Mass M
Computation:
1 km/h = 0.277778 m/s
So,
Initial velocity u = 66 km/h = 18.333
Final velocity v = 30 km / h = 8.333
Acceleration of this object a = [v - u]/t
Acceleration of this object a = [8.333 - 18.333]/2.5
Acceleration of this object a = -4 m/s²
Mass M = Force / Acceleration of this object a
Mass M = 400 / 4
Mass M = 100 kg
Is a nanoliter greater then one liter?
tại sao trái đất lại có trọng lực
Answer:
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what is the power of ideal sunglass
Which statement explains how constructive interference supports the wave model of light rather than the particle model?
O A. Light strikes a metal surface and knocks electrons loose, which particles would not do.
O B. Two light beams intersect, joining together to form a brighter beam, which is a behavior of waves.
O C. Two beams of light intersect, canceling each other out and forming a weaker beam, which is a behavior of waves.
O D. Light waves bend around a corner, but particles would not travel in bent paths.
Answer:
B. Two light beams intersect, joining together to form a brighter beam, which is a behavior of waves
Explanation:
Constructive interference of waves is the effect of the combination of two waves by the addition of their maxima and minima to produce a wave that has an amplitude which is the combination or the sum of the amplitudes of the two initially separate waves
Therefore, the statement, two light beams intersect, joining together to form a brighter beam, which is explainable by the constructive interference of waves, which is a wave behavior, supports the wave model of light rather than the particle model.
URGENT
A river flows toward 90°. Mark, a riverboat
pilot, heads the boat at 297º and is able to go
straight across the river at 6.0 m/s.
a. What is the velocity of the current?
b. What is the velocity of the boat as seen
from the river bank?
Four vehicles approach an intersection with a 4 way stop at the same time. Car B is ahead of Car A and both are in the same lane and want to proceed straight across. Car C is across the intersection from Car B and wants to proceed straight as well. Car D is to the right of Car B and wants to make a right turn. Which car must yield
Answer: car D
Explanation:
Define SI unit of measurement.
Answer:
the group of units suggested by the international convention of scientists in 1960 AD to make similarties in meseurment all over the world is called SI units
A 25.0 kg probe fell freely with acceleration of 2.00 m/s^2 just before it landed on a distant planet. What is the weight of the space probe on that planet
Answer:
The weight of the probe is 50 Newtons
Explanation:
Newtons second law states that F = ma
Given the mass of 25kg, and the acceleration of 2m/s^2, we can substitute both values into the equation to find the weight force.
[tex]F = ma[/tex]
[tex]F = 25 * 2[/tex]
[tex]F = 50N[/tex]
The weight of the probe is 50 Newtons
The maximum tensile force a solid, cylindrical wire can withstand increases as the thickness of the wire increases.
True
False
true
Explanation:
yes because as withstand increases as the thickness of the wire increases
CITEC Option. Work done will if no net force act on the body. (a) maximum (b) minimum (c) zero (d) all of above
quick answer
Explanation:
Yes, if force is acting on a body work done can be zero. When an object is at rest and no external force except gravity is acting on it in this case the work that would be zero as the force acting on it is perpendicular.
For example,
When an object is at rest and no external force except gravity is acting on it in this case the work that would be zero as the force acting on it is perpendicular. Therefore the displacement is zero and if displacement is zero work done would be zero.
We know that,
The work done
W=fs
Suppose that displacement is zero then,
W=f×0
W=0
The work done is zero.
An ice-skater with a mass of 80kg is holding a bowling ball with a mass of 8 kg. Suppose that the skater tosses the bowling ball forward with a speed of 6 m/s. What is the skater's reactive velocity? Show all work.
Answer:
0.6 m/s
Explanation:
The details of the masses and velocities are;
The mass of the ice skater, m₁ = 80 kg
The mass of the ball, m₂ = 8 kg
The speed with which the skater tosses the ball forward, v₂ = 6 m/s
Therefore;
According to the principle of conservation of linear momentum, we have;
m₁·v₁ = m₂·v₂
Where;
v₁ = The skater's reactive velocity
Therefore, we get;
80 kg × v₁ = 8 kg × 6 m/s
v₁ = 8 kg × 6 m/s/(80 kg) = 0.6 m/s
The skater's reactive velocity, v₁ = 0.6 m/s.
An object elongates from a length of 45 cm to a length of 55 cm. The percent strain is
41%
22%
122%
82%
18%
36%
Answer:
22%
Explanation:
55 - 45 = 10
10/45 simplifies to 2/9
2/9 = 0.22222... so 22.22% (rounded 22%)
what is the source of energy
The engine starter and a headlight of a car are connected in parallel to the 12.0-V car battery. In this situation, the headlight operates at 38 W and the engine starter operates at 2.40 kW. If the headlight and starter were then rewired to be in series with each other, what total power would they consume when connected to the 12.0-V battery
Answer:
The total power they will consume in series is approximately 2.257 W
Explanation:
The connection arrangement of the headlight and the engine starter = Parallel to the battery
The voltage of the battery, V = 12.0 V
The power at which the headlight operates in parallel, [tex]P_{headlight}[/tex] = 38 W
The power at which the kick starter operates in parallel, [tex]P_{kick \ starter}[/tex] = 2.40 kW
We have;
P = V²/R
Where;
R = The resistance
V = The voltage = 12 V (The voltage is the same in parallel circuit)
For the headlight, we have;
R₁ = V²/[tex]P_{headlight}[/tex] = 12²/38 = 72/19
R₁ = 72/19 Ω
For the kick starter, we have;
R₂ = V²/[tex]P_{kick \ starter}[/tex] = 12²/2.4 = 60
R₂ = 60 Ω
When the headlight and kick starter are rewired to be in series, we have;
Total resistance, R = R₁ + R₂
Therefore;
R = ((72/19) + 60) Ω = (1212/19) Ω
The current flowing, I = V/R
∴ I = 12 V/(1212/19) Ω = (19/101) A
We note that power, P = I²R
In the series connection, we have;
[tex]P_{headlight}[/tex] = I² × R₁
∴ [tex]P_{headlight}[/tex] = ((19/101) A)² × 72/19 Ω = 1368/10201 W ≈ 0.134 W
The power at which the headlight operates in series, [tex]P_{headlight, S}[/tex] ≈ 0.134 W
[tex]P_{kick \ starter}[/tex] = ((19/101) A)² × 60 Ω = 21660/10201 W ≈ 2.123 W
The power at which the kick starter operates in series, [tex]P_{kick \ starter, S}[/tex] ≈ 2.123 W
The total power they will consume, [tex]P_{Total}[/tex] = [tex]P_{headlight, S}[/tex] + [tex]P_{kick \ starter, S}[/tex]
Therefore;
[tex]P_{Total}[/tex] ≈ 0.134 W + 2.123 W = 2.257 W
