Answer:
a. 960 W b. One 1 kW room heater
Explanation:
a. The rate of heat conduction P = kA(T₂ - T₁)/d where k = 2 × 0.040 W/m-K = 0.080 W/m-K since the thermal conductivity of glass wool is 0.040 W/m-K and that of the material is twice the thermal conductivity of glass wool, A = area of walls = 120 m², T₁ = outside surface temperature = 5.0 °C, T₂ = inside surface temperature = 18.0 °C and d = thickness of wall = 13.0 cm = 0.13 m
P = kA(T₂ - T₁)/d
= 0.080 W/m-K × 120 m²(18.0 °C - 5.0 °C)/0.13 m
= 9.6 Wm/K × 13 K/0.13 m
= 124.8 Wm/0.13 m
= 960 W
b. The number of 1 kW room heater required will be
n = rate of heat conduction/power of one room heater = 960 W/ 1 kW = 960 W/1000 W = 0.96 ≅ 1
So we need only one 1 kW room heater.
a metre rod on wedge is example of unstable equilibrium.why
Answer:
because it has no balance
Which term describes the ability to process many things simultaneously?
O Effortful processing
O Parallel processing
O Mood congruent memory
O Flashbulb memory
O Working memory
Answer:
Parallel processing
Explanation:
It is a parallel processing because it involves the brain processing many part of problem simultaneously.
The brain natural mode of information involves performing many task .
It is also ability of the brain to simultaneously process incoming stimuli or signals of different quality. It is a part of brain's vision and divide what is seen into four major parts which are color, motion, shape, and depth.
Answer: B) Parallel processing
Astronomers were at first surprised to find complicated molecules in the interstellar medium. They thought ultra-violet light from stars would break apart such molecules. What protects the molecules we observe from being broken apart
Answer:
The dust present in the clouds.
Explanation:
The complicated composition molecules that can be found in space are generally associated with clouds of dust. The significant amount of dust in these clouds provides protection not only for these molecules, but for any body that makes up or is associated with dust clouds.
It is exactly this dust that protects the molecules against the action of ultraviolet rays.
how do you find average velocity
Answer:
find the sum of the inital and final velocitys and divide by 2 to find the average
we hammer the broader side of a nail and not its sharp end to put it in wood .why ?
Explanation:
We hammer the broader side of a nail instead of its sharp end to put it in wood. It is a concept based on the pressure exerted.
The force acting per unit area of an object is called pressure exerted. It means that pressure is inversely proportional to the area of cross section i.e. area increases, pressure decreases and vice versa.
The broader side of a nail has more area as compared to the sharp end. It means that the broader side will exert less pressure on them which make it easier for us to fix it into the wood.
A square is cut out of a copper sheet. Two straight scratches on the surface of the square intersect forming an angle theta. The square is heated uniformly. As a result, the angle between the scratches?a) increasesb) decreasesc) stays the samed) depends on whether theta is obtuse or acute
Answer:
a) increases
Explanation:
Almost all substance or material undergoes expansion due to heating. Heat gives thermal energy to the molecules of a substance increasing their body temperature. The temperature of a substance is the measure of the average kinetic energy of the molecules of that substance. When the temperature of a substance increases, the molecules begin to agitate and try to move far from each other, leading to either a linear, area, or cubic expansion, or all three of them. Metals like copper expand very well on heating, and their expansion is relatively minute, but very observable. When the face of such a copper is scratched to give and angle, heating the copper uniformly will cause the copper to expand, leading to an increase in the angle formed.
A man of mass 75kg stands on a weighing machine in a lift. Determine the reading of the weighing machine when the lift is moving: 1. Upwards with an acceleration of 2m/s² 2. Downwards with a constant velocity of 1.5m/s 3. Downwards with an acceleration of 2.5m/s²
Explanation:
Given that,
Mass of a man, m = 75 kg
(1) We need to find the reading of the weighing machine when the lift is moving upwards with an acceleration of 2 m/s². When the lift is moving upward, reading of the weighing machine is given by :
R = m(g+a)
R = 75 (9.8+2)
R = 885 N
(2) When the lift is moving downwards with a constant velocity of 1.5m/s. It means that the lift is at rest. So, the reading is :
R = mg
R = 75 (9.8)
R = 735 N
(3) When the lift is moving downwards with an acceleration of 2.5 m/s². In this case,
R = m(g-a)
R = 75 (9.8-2.5)
R = 547.5 N
Hence, this is the required solution.
A magnet pulls a piece of iron with a force of 1 N. What is the force that the iron piece exerts on the magnet?
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the same direction.
The iron piece exerts a force of 1 N on the magnet in the opposite direction.
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the opposite direction.
The iron piece exerts a force of 1 N on the magnet in the same direction.
Answer:
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
Explanation:
In this exercise they give us the force exerted by a magnet on an iron bar and ask us the force that the iron bar exerts on the magnet. We can see that these are action and reaction forces, which by Newton's third law must be of equal magnitude and opposite direction, each applied to one of the bodies.
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
An object is moving along a circular track of radius 7 m with constant speed 11 m/s. Its average velocity after 8 second of the start is
Answer:
0 m/s
Explanation:
Average velocity is displacement over time.
v_avg = Δx / Δt
Displacement is the distance between the start and the finish.
The circumference of the track is:
C = 2πr
C = 2π (7 m)
C ≈ 44 m
The distance covered by the object is:
d = vt
d = (11 m/s) (8 s)
d = 88 m
So the object travels 2 circumferences, meaning it ends back where it started. Therefore, the displacement is 0 m, and the average velocity is 0 m/s.
A ball is thrown vertically upwards at an initial speed of
23
m s
−
1
. What is the displacement of the ball 3 seconds after it was thrown?
Answer:
114m
Explanation:
s=ut + 1/2 at^2
s=23 m/s ×3s + 1/2×3×3s^2×10m/s^2
= (69+45)m
= 114m
Please Help
A skydiver jumps out of a hovering helicopter, so there is no forward velocity. Use this information to answer questions. Ignore wind resistance for this exercise.
3. What is the skydiver's velocity after one second? Show your work and include direction.
Answer:
The velocity and direction after 1 second is 8.1 m/s downwards
Explanation:
The equation of motion for an object in free fall can be written as follows;
v = u + g×t
Where;
v = The final velocity of the object
u = The initial velocity of the object = 0 m/s
g = The acceleration due to gravity = 9.81 m/s²
The velocity after one second is given by the velocity equation as follows;
v = 0 + 9.81 m/s² * 1 s = 9.81 m/s
The direction of the is downwards due to the attraction by the Earth's gravitational field which acts towards the Earth's center
Therefore, the velocity and direction after 1 second is 8.1 m/s downwards.
A physical inventory on December 31 shows 3500 units on hand. Bonita sells the units for $15 each. The company has an effective tax rate of 20%. Bonita uses the periodic inventory method. The weighted-average cost per unit is
what is the scientific notation for 1,500,000
Answer:
[tex]1.5 * 10^6[/tex]
Explanation:
Given
Digit: 1,500,000
Required
Represent using scientific notation
We start by expressing the given digit as a product of 1.5 and a multiple of 10
[tex]Digit = 1.5 * 1,000,000[/tex]
1,000,000 can be represented as 10⁶
So; the digit becomes
[tex]Digit = 1.5 * 10^6[/tex]
Hence, the scientific notation of 1,500,000 is 1.5 * 10⁶
What evidence supported the inflation theory? (the big bang theory one pls)
Answer:
The comic microwave background
Explanation:
The cosmic microwave background is said to be part of the remnant of the Big Bang that happened which resulted in the formation of the universe. This is because the universe was thought to be a very hot place which resulted in the expansion of it.
The heat was said to have resulted in the cooling of gases present and the remnant of the heat is what formed the radiation called the cosmic wave background.
Un pez llamado PARGO ROJO vive a grandes profundidades. Si se pesca, al salir a la superficie puede tomar el aspecto de la foto porque su vejiga natatoria aumenta de volumen al disminuir la presión. La ley que lo explica es...
Answer:
Hay diversas leyes que podemos usar acá.
Acá sabemos que la vejiga aumenta su tamaño al reducir la presión, esto tiene sentido, pues al haber menos presión, hay menos fuerza que comprime la vejiga, lo que le permite aumentar su volumen.
Acá tenemos una relación inversa de la forma: V = K/P
Una relación inversa donde la presión esta en el denominador y K es un termino que no depende ni del volumen ni de la presión.
Entonces, a medida que aumenta P, el denominador aumenta, por lo que el valor del volumen decrece.
Un ejemplo de una ecuación similar es la del gas ideal, por ejemplo, para un gas ideal dentro de un globo de volumen V para una dada presión P:
V = nRT/P
donde n es el numero de moles, R es la constante termodinámica y T es la temperatura, acá podemos ver que esta ecuación tiene la misma forma fundamental que la escrita arriba.
The motion of a particle along a straight line is described by the equation x=6+4t2 -t 4 , where x is in meter and t is in seconds. Find position, velocity, and acceleration of the object when t=2s.
Answer:
The position of the particle is 6m
The velocity of the particle is 16 m/s in negative direction
The acceleration of the object is -40 m/s²
Explanation:
Given;
motion of the particle along a straight line as x = 6 + 4t² - t⁴
The position of the object when t = 2s
x = 6 + 4(2)² - (2)⁴
x = 6 + 16 - 16
x = 6m
The velocity of the object when t = 2s
Velocity = dx/dt
dx/dt = 8t - 4t³
when t = 2s
Velocity = 8(2) - 4(2)³
Velocity = 16 - 32
Velocity = -16m/s
Velocity = 16 m/s (in negative direction)
The acceleration of the object when t = 2s
Acceleration = d²x/dt² = 8 - 12t²
Acceleration = 8 - 12 (2)²
Acceleration = -40 m/s²
Question is on the picture. Answers: A. 0.1 J/g*C B. 0.2 J/g*C C. 0.4 J/g*C D. 4 J/g*C
Answer:
B. 0.2 J/g/°C
Explanation:
The solid phase is the first segment (from 0°C to 50°C).
q = mCΔT
200 J = (20 g) C (50°C)
C = 0.2 J/g/°C
Please give best dialogue in photo that is attached And you are marked as Brainliest
Answer:
The correct answer is
Explanation:
Character 1: Why are these comic books so hard to read? Can u read them?
Character 2: No it's easy to read Tigger. It's because you are an animal an I am a human being. U don't know how to read.
Hope this helps....
Have a nice day!!!!
Answer:
Dialogue 1:
Hey buddy! Can you tell me what is written in this book? Its really hard to read:(
Dialogue 2:
Yeah! Its a story about a friendly tiger! And it is hard for you to read cause you don't know how to read.
Tip:
Try to make it more engaging :)
A wave has a frequency of 5 Hz and a wavelength of 0.5 m, what is the speed of this wave?
Answer:
2.5 m/s
Explanation:
The speed of a wave can be found using the following formula.
v= λ * f
where λ is the wavelength in meters (m) and f is the frequency of the wave in Hertz (Hz).
We know the wavelength is 0.5 m and the frequency of the wave is 5 Hz.
Therefore,
λ= 0.5 m
f = 5 Hz
v= 0.5 * 5
Multiply 0.5 by 5, or divide 5 by 2.
0.5 * 5= 2.5 or 5/2=2.5
v= 2.5
Add appropriate units. The units for wave speed are m/s (meters per second).
v= 2.5 m/s
The speed of the wave is 2.5 meters per second.
1. Determina el momento que produce una fuerza de 7 N tangente a una rueda de un metro de diámetro, sabiendo que el punto de aplicación es el mismo borde de dicha rueda provocando un impulso en el sentido de las agujas del reloj. Solución:
Answer:
τ= F r into the blade
Explanation:
The moment of a force is defined by
τ = F x r
where the bold indicates vectors
Let us write in the expression in magnitude
τ = F r sin θ
in our case the force is tangent to the wheel therefore the angle between F and the radius is 90º, and the sin 90 = 1
τ= F r
The direction of τ can be used by the rule of the right hand, the fingers curve in the direction of the torque when advancing from the force to the radius and the thumb points in the direction of the torque.
In this case, for a clockwise rotation, the fingers are curved in the direction and the thumb points into the blade, this is the direction of the τ.
TRASLATE
El momento de una fura es definido por
τ = F x r
donde la negrillas indican vectores
Escribamos en ta expresión en magnitud
τ = F r sin θ
en nuestro caso la fuerza es tangente a la rueda por lo tanto el angulo entre F y el radios es 90º, y el sin 90=1
τ = F r
la dirección de tau la podemos usar la regla de la mano derecha, los dedos curva en la dirección del torque al avanzar dese la fuerza al radio y el pulgar apunta en la dirección del torque.
En este caso para un giro en sentido horario los dedos se curvan ente sentido y el pulgar apunta hacia dentro de lla hoja, esta es la dirección del troque
Jaiden is writing a report about the structure of the atom in her report,she says that the atom has three main parts and two subatomic particles. Do you agree with her?why or why not
Answer:
I do not agree with the answer.
Because in reality, the atom has 2 main parts and 3 subatomic particles.
Explanation:
The parts of an atom are:
- The crust: It is the outer part of the atom and is the place where the electrons are.
- The nucleus: It is the central part of the atom and is the place that contains the protons and neutrons.
The subatomic particles of the atom are:
- Electrons: They are negatively charged particles that go in the atom's crust and are divided into specific sections.
- Protons: They are particles with a positive electric charge, the number of protons in the nucleus of an atom is what determines the atomic number of an element.
- Neutrons: They are atoms with no electric charge.
Which example best describes a restoring force?
any force that is applied to a spring to change its length
the force applied to stretch a spring and increase its length
the force applied to restore a spring to its original length
the force applied to compress a spring and shorten its length
Answer:
the force applied to restore a spring to its original length
Explanation:
A cell membrane has a thickness of about 7 nm. How many cell membranes would it take to make a stack 2.3 in high?
Answer:
There are 8345714 cell membranes.
Explanation:
It is given that,
The thickness of a cell membrane is 7 nm
We need to find the number of cell membranes would it take to make a stack 2.3 inches high.
Firstly, the units must be same i.e. converting 2.3 inches to m
1 inch = 0.0254 m
2.3 inches = 0.05842 m
Let there are n number of cell membranes. So,
[tex]n=\dfrac{\text{stack height}}{\text{1 membrane thickness}}\\\\n=\dfrac{0.05842}{7\times 10^{-9}}\\\\n=8345714.28[/tex]
or
n = 8345714 cell membranes
state three effects of malnutrition in farm animals
Answer:
Cows,Pigs,Chicken. They are always in farm
i) A 100 W and 60 W bulb are joined in series and connected to the mains. Which bulb
will glow brighter? Why?
ii) A 100 W and a 60 W bulb are joined in parallel to the mains. Which bulb will
glow brighter? Why?
Answer:
i) 60 W
ii) 100 W
Explanation:
In each case, the bulb that dissipates the most power is the bulb that glows brighter. Power is voltage times current (P = VI). Using Ohm's law, we can rewrite this as P = I²R or P = V²/R.
Bulbs are rated at a certain power for a certain voltage. P = V²/R, so the bulb with the lower resistance will have the higher power rating. Therefore, the 100 W bulb has a lower resistance than the 60 W bulb.
i) They are in series, so they have the same current. P = I²R, so the bulb with the higher resistance will glow brighter. That's the 60 W bulb.
ii) They are in parallel, so they have the same voltage. P = V²/R, so the bulb with the lower resistance will glow brighter. That's the 100 W bulb.
describe three way of nitrogen fixation in nature ?
Explanation:
nitrogen fixation is the process by which nitrogen gas form the atmosphere is converted into different compound that can be used by plants and animal. there are three major ways in which this happens: first, by lightning, second by industrial methods and finally by bacteria living in the soil.
calculate the power of an engine which can supply 60kg of energy per minute
Answer:
1 Watt
Explanation:
Power (P) = w / Δt
w = work done
Δt = change in time
Power (P) = 60kg / 60 seconds
Power (P) = 1 Watt
the unit of energy is a derived unit
Explanation:
Hi, there!!
Energy is defined as the capacity or ability to do work. It's SI unit is Joule.
here,
Joule = (kg×m×m)/(s×s)
= kg×m^2/s^2.
Therefore, the derived unit is kg.m^2 by s^2.
Hope it helps...
explore how archemides principle is applied in building a ship and submarine
Answer:
Principle Archimedes is applied in building a ship and submarine using the manipulating that buoyancy, is controlled the ballast tank system.
Explanation:
Submarine is rather had they focused on main parts of the submarine,he is complex and long process implementation,the most submarine design like submarine stability.
Submarine stability is complete and the fundamental Archimedes principle to arrive the weight of submarine is equal to buoyancy force.
Submarine into the parts and components of ballast tank the sequence in diving and surfacing,there two vital parts:- flood parts and air vents
flood parts:- at the bottom position and allow water to enter or leave that tank.
air vents:- air vents at the top of the pressure hall,and that they submarine dive.
this time submarine is most modern system is depth is 300 to 450 meters,high pressure air is 15 bar is tank air valve.
submarine is basic of the effective volume of all the submarine surfaced condition,submarine minus to the free water flood is equal to the fully pressure hull,submarine is the surfaced condition.
Earth orbits 1 AU from the Sun, and the Oort cloud extends from about 10,000 to 100,000 AU from the Sun. If you represent Earth’s orbit around the Sun with a paper plate 4 inches in radius, how far away will the inner edge of the Oort Cloud be? The outer edge? Express your answers in miles.
Explanation:
Earth’s orbit around the Sun represented as :
1 AU = 4 inches
Therefore,
Inner edge of the Oort Cloud represented as :
10,000 AU = 40,000 / 63360 = 0.631 miles
Outer edge of the Oort Cloud represented as:
100,000 AU = 400,000 / 63360 = 6.31 miles
