Why are houses in hot areas painted in white while those in cold areas painted with dull colours
Answer:
Because white color reflects back the heat coming from the sun while dull colors absorb the heat.
A large atomic bomb produces around 8.00x1015J of energy. How much matter does that bomb turn into energy?
A)2.67x10^79kg
B)2.67x10^7kg
C)7.20x10^32kg
D)0.0889kg
Answer:
D)0.0889kg
Explanation:
If a large atomic bomb produces around 8.00x10¹⁵J of energy, then from Einstein's energy law i.e E=mc² we can calculate that the amount of matter is 0.0889kg. The correct option is D.
What is Einstein's energy law?
The Einstein Energy Law, often referred to as Einstein's famous equation relates the energy of a particle (E) to its mass (m) and the speed of light (c). The equation is as follows:
E = mc²
This equation shows that energy (E) and mass (m) are equivalent and interchangeable and that a small amount of mass can be converted into a large amount of energy. This is the basis for understanding nuclear reactions and the energy released in processes like nuclear fusion and fission.
Here in the question,
To calculate the mass that is converted into energy in an 8.00x10¹⁵J nuclear reaction, we can rearrange the equation to solve for m:
m = E / c²
where c = 3 x 10⁸ m/s is the speed of light in a vacuum.
Substituting the values, we get:
m = 8.00x10¹⁵ J / (3 x 10⁸ m/s)²
m = 0.0889kg
Therefore, a large atomic bomb that produces around 8.00x10¹⁵ J of energy converts approximately 0.0889kg of matter into energy. This is a very small amount of matter, but because c² is such a large number, a huge amount of energy can be released from a small amount of matter in a nuclear reaction.
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We use __force to do different force. 1) pulling 2)pushing 3)gravity 4)muscular
Answer:
gravity
Explanation:
We use gravity to do different force.
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.
if you add km/ hr with another km/ hr what will you get
Answer:
km/hr
Explanation:
Addition and subtraction are commutative
Meaning you can add or subtract in any order because it doesn't change the sum or the difference. So it doesn't change the units.
Answer:
km/ hr + km/ hr =(km+ km)/hr=2km/hr
Explanation:
power of a lens whose focal length is -40 d.
Answer:
as we know
p=1/f
p=1/-40m
p= -0.025d
you have written the unit of focal length wrong it is the unit of power
please mark as brainliest plzzzzzzzzzz
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]
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
Two charges 3*10^-5 C and 5*10^4 C are placed at a distance 10 cm form each other. Find the value of electrostatic force acting between them. a) 13.5 x 10^11N b) 40 x 10^11N c)180 x 10^9N d)13.5 x 10^10 N
Answer:
13.5 x 10^(11) N
Explanation:
Given :
The magnitude of charge 1 = q1 = 3 × 10^(-5) C
The magnitude of charge 2 = q2 = 5 × 10^(4) C
The distance between charges = d = 10 cm = 0.1 m
To Find :
The magnitude of electrostatic force acting between charges
Solution :
∵ Electrostatic force = F = (k × (q1) x (q2)) / r^(2)
where k = 9 × 10^(9)
i.e F = 9 × 10^(9) × (3 × 10^(-5) × 5 × 10^(4)) / (0.1)^(2)
Or, F = 9 × 10^(9) × (1.5/0.01)
∴ F = 9 × 10^(9) × 150
i.e F = 1350 × 10^(9)
or, Force = F = 1.35 × 10^(12) N
Hence, The magnitude of electrostatic force acting between charges is 1.35 × 10^(12) N => 13.5 x 10^(11)
20. A semiconductor is a
A) crystalline solid that conducts current under any condition
B) metallic solid that conducts current under any condition
C) metallic solid that conducts current under certain conditions
D) crystalline solid that conducts current under certain conditions
Answer:
D) crystalline solid that conducts current under certain conditions
Explanation:
A semiconductor is any crystalline solid material whose electrical conductivity is intermediary between that of insulators and conductors. That is, a semiconductor does not conduct like a conductor but does more than an insulator.
Based on this, a semiconductor is said to only conduct electricity under certain conditions as opposed to conductors that do so under any condition. Example of semiconductors are silicon, carbon, antimony, arsenic etc.
When the system pressures are lower than the pressure in the refrigerant tank, such as when the system has just been evacuated or if the system is out of refrigerant, refrigerant can be added to both the high and low pressure sides of the system. A. True B. False
Answer: True
Explanation:
It should be noted that when refrigerant is added in vapor form to the operating refrigeration system, then the addition of the refrigerant should be to the low-pressure side of the refrigeration system.
Furthermore, when system pressures are lower than the pressure in the refrigerant tank as stated in the question, then the refrigerant can be added to both the high and low pressure sides of the system.
Therefore, the correct option is true.
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
2. ¿Puede haber trabajo en un sistema si no hay movimiento
a. Sí, si hay una fuerza siempre.
b. Sí, ya que el movimiento es sólo relativo.
c. No, ya que un sistema que no se mueve no tiene energía.
d. No, porque la ecuación de trabajo lo define.
Answer:
d. No, porque la ecuación de trabajo lo define.
Explanation:
En Física, el trabajo realizado se puede definir como la cantidad de energía transferida cuando un objeto o cuerpo se mueve a lo largo de una distancia debido a la acción de una fuerza externa.
Matemáticamente, el trabajo realizado viene dado por la fórmula;
[tex] W = F * d [/tex]
Dónde;
W es el trabajo realizado.F representa la fuerza que actúa sobre un cuerpo. d representa la distancia recorrida por el cuerpo.Por lo tanto, podemos deducir de la definición de trabajo y su fórmula que el trabajo se realiza cuando un objeto (cuerpo) se mueve una distancia o experimenta cualquier forma de desplazamiento mientras transfiere energía.
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
According to Moseley, the properties of elements are a
periodic function of their
Answer:
According to Henry Moseley, Atomic number is the fundamental property of the elements because elements are made up of atoms . ... So the physical and chemical properties of elements are periodic functions of their atomic number.
Use the equation d=st where d= distance, s= speed, and t= time. If you ride a skateboard at a speed of 8m/s for 12 seconds, how far do you travel
Answer:
96 meters
Explanation:
d = st
d = (8 m/s)(12 s)
d = 96 m
define mass defect and binding energy
Answer:
About Transcript. Nuclear binding energy is the energy required to split an atom's nucleus into protons and neutrons. Mass defect is the difference between the predicted mass and the actual mass of an atom's nucleus. The binding energy of a system can appear as extra mass, which accounts for this difference.
Explanation:
PLZ MARK AS THE BRAINLIEST
I NEED IT URGENTLY
HAVE A GOOD DAY
MAY GOD BLESS U
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2. Speed limits on curves help to reduce the effect of ........force on a vehicle
A. enertia
b. centrifugal
c. gravity
Answer:
enertia
Explanation:
enertia
The correct answer is (B) Centrifugal Force
The centrifugal force on a vehicle on the curves is outwards or can say away from the curve and pulls the out of the track.
the centrifugal force is given by [tex]F=\frac{mv^{2} }{r}[/tex], which is directly proportional to speed v.
Speed limits on the curves help in reducing the centrifugal force by reducing the speed.
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personal and unbiased errors belong to
personal to systematic errors
unbiased to random errors
(a) What kind of energy is possessed by an aeroplane flying at a height of 10000 m?
Answer:
When the plane is rest position it possess potential energy. But when a aeroplane is flying at the height it possess kinetic energy. No matter what height is given.
mention various medium level and higher level human resources related to engineering.
Answer:
Higher-level human resources related to engineering are those who:
Assist other engineers with solving complex problems. Work with management to keep the project on track. Mentor younger engineersMedium Level engineers will normally comprise the following:
They are responsible for developing engineering plans and performing calculations with respect to the same. Project workflow management Engineering Support facilitation Project Reporting Coordination of Team MembersCheers
Luis rushes 40m toward his truck. He notices he forgot his shoes and returns back to his house. His total travel time is 60s.
What is Luis’s average speed over the 60s?
What is Luis average velocity over the 60s?
1. The average speed of Luis over the 60 s is 1.33 m/s
2. The average velocity of Luis over the 60 s is zero.
1. The average speed can be calculated with the following equation:
[tex] S = \frac{d}{t} [/tex]
Where:
d: is the total distance traveled
t: is the total time = 60 s
The total distance can be calculated by the sum of the distance traveled to the truck (40 m) and the distance traveled to his home (the same 40 m), as follows:
[tex] d = 40 m + 40 m = 80 m [/tex]
So, the average speed is:
[tex] S = \frac{d}{t} = \frac{80 m}{60 s} = 1.33 m/s [/tex]
Hence, Luis's average speed over the 60 s is 1.33 m/s.
2. Now, the average velocity is a vector given by:
[tex]v = \frac{\Delta x}{\Delta t} = \frac{x_{f} - x_{i}}{t}[/tex]
Where:
[tex]x_{f}[/tex]: is the final distance traveled (the way to his home) = 40 m
[tex]x_{i}[/tex]: is the initial distance traveled (the way to his truck) = 40 m
Δt: is the total time = t = 60 s
Given that Luis in his journey, returns to the same starting point (his house), the total displacement is zero, and so the average velocity is also zero:
[tex]v = \frac{x_{f} - x_{i}}{t} = \frac{40 m - 40 m}{60 s} = 0[/tex]
Therefore, Luis's average velocity over the 60 s is zero.
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As shown in the figure below, Luis rushes 40 m toward his truck. He notices he forgot his shoes and returns back to his house. His total travel time is 60 s.
Answer:
What is Luis’s average velocity over the 60 s period?
Answer: 0 m/s
What is Luis’s average speed over the 60 s period?
Answer: 1.33 m/s
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
a car moves at a speed of 40km/h. it is stopped by applying brake which produce a uniform acceleration of-0.5m/s^2. how much distance will it move before coming to stop ?
Answer:
Explanation:
We first need to convert the 40 km/h to m/s. Going by the fact that 40 has only 1 significant figure in it, 40 km/h = 10 m/s. The rest of the values are in their proper labels. We will use the equation:
[tex]v^2=v_0^2+2a[/tex]Δx where the final velocity is 0 because the car is coming to a stop at the end; the initial velocity is 10 m/s, the acceleration (or, rather, deceleration) is -.5 m/s/s, and our unknown which is displacement. Filling in:
[tex]0=(10)^2+2(-.5)[/tex]Δx and solving for Δx:
Δx = [tex]\frac{-100}{2(-.5)}[/tex] which ends up being simply that
Δx = 100 m
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
A CROW BAR WITH LENGTH 200 CM IS USED TO LIFT A LOAD OF 600N . IF THE DISTANCE BETWEEN FULCRUM AND LOAD IS 0.75. CALCULATE ; a, effort b, MA c, VR
Answer:
a. Effort = 960 Newton
b. Mechanical advantage (M.A) = 0.625
c. Velocity ratio (V.R) = 1.67
Explanation:
Given the following data;
Load = 600 NLength of crowbar = 200 cmLength of load arm = 0.75 mConversion:
100 cm = 1 m
X cm = 0.75 m
Cross-multiplying, we have;
X = 0.75 * 100 = 75 cm
First of all, we would find the effort arm;
Effort arm = length of crow bar - length of load arm
Effort arm = 200 - 75
Effort arm = 125 cm
Next, we would determine the mechanical advantage (M.A) of the crow bar;
[tex] M.A = \frac {Effort \; arm}{Load \; arm} [/tex]
Substituting the values into the formula, we have;
[tex] M.A = \frac {125}{200} [/tex]
M.A = 0.625
To find the effort of the crow bar;
[tex] M.A = \frac {Load}{Effort} [/tex]
Making "effort" the subject of formula, we have;
[tex] Effort = \frac {Load}{M.A} [/tex]
[tex] Effort = \frac {600}{0.625} [/tex]
Effort = 960 Newton
Lastly, we would determine the velocity ratio (V.R);
[tex] V.R = \frac {length \; of \; effort \; arm}{length \; of \; load \; arm} [/tex]
[tex] V.R = \frac {125}{75} [/tex]
V.R = 1.67
The direction of applied force has to be .............. to the distance in order to say work is done
Answer:
Parallel
Explanation:
The work done is defined as the force applied on an object and the displacement in the position of the object in the direction of force.
W = F s cos A
where, F is the force, s is the displacement and A is the angle between force and displacement.
When the angle between the force and the displacement is 90 degree, the work done is zero.
To get the maximum work the angle between the force and the displacement is 0 degree.
So, to get the work done by the force the angle between the force and displacement is 0 degree that means the force and displacement is parallel to each other.
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 we aim a radio telescope at a distant spiral arm of the Milky Way Galaxy, we will probably observe a 21-cm line. If we point a large optical telescope at this same region, we will probably not be able to detect the neutral hydrogen that gives rise to the 21-cm radio signal. Why not
Answer:
Because of the interstellar dust and interior location of the solar system.
Explanation:
We will probably not be able to detect the neutral hydrogen that gives rise to the 21-cm radio signal if we point a large optical telescope to the region because, the interstellar dust obscures the location of the spiral arm of the Milky way galaxy and this makes neutral hydrogen that gives rise to the 21-cm radio signal difficult to detect.
Also, the interior location of the solar system also makes the neutral hydrogen that gives rise to the 21-cm radio signal difficult to detect.
So, the interstellar dust and the interior location of the solar system makes it difficult to detect the neutral hydrogen that gives rise to the 21-cm radio signal with a large optical telescope.
A 550N object has a coefficient of .012 against a smooth surface. What
force is needed to keep the object sliding?(ANSWER to 1 decimal place, no
units)
Vertically, the object is in equilibrium, so that the net force in this direction is
∑ F (vertical) = n - mg = 0
where n is the magnitude of the normal force due to the contact between the object and surface. You're given that the object's weight is mg = 550 N, so n = 550 N as well.
Horizontally, the net force would be
∑ F (horizontal) = p - f = 0
where p is the magnitude of the applied force and f is the magnitude of (kinetic) friction opposing p. Now,
f = 0.012n = 0.012 (550 N) = 6.6 N
so that you need to apply a force of p = 6.6 N to keep the object sliding at a steady pace.
