Kevin used a pulley to lift a piano to the third floor of his apartment. His input work was 12,000 J and the output work was 10,000 J. What was the mechanical efficiency of the pulley?
A . 50%
B. 83.3%
C . 120%
D. 16.7%
Answer:
B
Explanation:
Eff = output work/input work ×100
Hence, Eff = 10000/12000 × 100
Eff = 83.3%
Describe the advantages and disadvantage is of living in a floodplain
Answer:
:) :::::::::::::::::::::::::::::::))))
why physics ought to be studied?
Answer:
The goal of physics is to understand how things work from first principles. ... Courses in physics reveal the mathematical beauty of the universe at scales ranging from subatomic to cosmological. Studying physics strengthens quantitative reasoning and problem solving skills that are valuable in areas beyond physics.
Light of wavelength 530.00 nm is incident normally on a diffraction grating, and the first‑order maximum is observed to be 33.0∘ from the normal. How many slits per millimeter are marked on the grating?
Answer:
1028 slits/mm
Explanation:
We are given that
Wavelength of light, [tex]\lambda=530nm=530\times 10^{-9} m[/tex]
1nm=[tex]10^{-9} m[/tex]
[tex]\theta=33^{\circ}[/tex]
n=1
We have to find the number of slits per mm are marked on the grating.
We know that
[tex]dsin\theta=n\lambda[/tex]
Using the formula
[tex]dsin33^{\circ}=1\times 530\times 10^{-9}[/tex]
[tex]d=\frac{530\times 10^{-9}}{sin33^{\circ}}[/tex]
[tex]d=9.731\times 10^{-7} m[/tex]
1m=[tex]10^{3}mm[/tex]
[tex]d=9.731\times 10^{-7}\times 10^3[/tex]mm
[tex]d=0.0009731mm[/tex]
Number of slits=[tex]\frac{1}{d}[/tex]
Number of slits=[tex]\frac{1}{0.0009731}[/tex]/mm
Number of slits=1028/mm
Hence, 1028 slits/mm are marked on the grating.
Answer:
1027.6 lines per mm.
Explanation:
wavelength = 530 nm
order, m= 1
Angle = 33 degree
Let the slits per mm is 1/d.
So,
[tex]m \lambda = d sin A\\\\1\times 530\times 10^{-6} = d sin 33\\\\\frac{1}{d} = 1027.6 lines per mm[/tex]
An unbalanced 6.0-newton force acts eastward on an object for 3.0 seconds. The impulse
produced by the force is
18 N:s east
2 Nós east
18 N:s west
2 Nis west
The mass of a brick is 2kg. Find the mass of water displaced by it when it is completely immersed in water. (Density of the bricks is 2.5 g/cm^3)
Answer:
2000g
Explanation:
volume=mass/density
=2000/2.5
=800cm³
mass=density×volume
=800×2.5
=2000g
why solid keep their shape?
Answer:
Solids can hold their shape because their molecules are tightly packed together. ... Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want. The molecules in a solid are stuck in a specific structure or arrangement of atoms
Hope this helps ☆*:. o(≧▽≦)o .:*☆
Compared with dim light, what do light waves that look bright tend to have the subject just says science but the picker doesn't have that
Answer:
The brightness of a light depends on the amplitude of the light wave, which is the extent the waves moves from their equilibrium position. The brightness is also related to the amount of light that is emitted or reflected by an object
Therefore, compared to dim light, light that look bright have a higher amplitude and emit or reflect more light energy (photons)
Explanation:
16 100 g of water at 25 °C is poured into an insulating cup. 50 g of ice at 0 °C is added to the water.
The water is stirred until the temperature of the water has fallen to 0°C.
18 g of ice remains unmelted.
The specific heat capacity of water is 4.2 J /g °C.
Which value does this experiment give for the specific latent heat of fusion of ice?
Answer:
Q = Q
mcT = ml
100 x 4.2 x 25 = (50-18) l
l = 328
*Hope it helps*
The specific latent heat of fusion of the melted ice is 328.13 J/kg.
Conservation of energy
The specific latent heat of fusion of the melted ice is determined by applying the principle of conservation of energy as shown below;
Heat lost by the water = Heat gained by the ice
McΔθ = mL
where;
c is specific heat capacity of waterL is pecific latent heat of fusion of icem is mass of melted ice = 50 g - 18 g = 32 g(100)(4.2)(25) = (32)L
32L = 10500
L = 328.13 J/kg
Thus, the specific latent heat of fusion of the melted ice is 328.13 J/kg.
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What is the difference between heat capacity and specific heat capacity? I want the meaning please.
Answer:
The heat capacity of a body is defined as the heat required to raise it's temperature by me degree or one kelvin.while specific heat capacity of a substance is defined as the heat required to the temperature of a unit mass of it through one degree or one kelvin.
I hope it helps
Magnetic force between the north poles of two magnets is
Magnetic force between the north poles of two magnets is REPULSIVE
Answer:Repulsion or attraction
Explanation:The angle between the compass needle and geographic north is called the MAGNETIC DECLINATION.(see earth:the magnetic field of the earth ). The repulsion or attraction between two magnetic dipoles can be viewed as the interaction of one dipole with the magnetic field produced by other dipole.
A convex mirror of radius of curvature 1.6 m has an object placed at a distance of 1.0 m from it. Find the position of image and the magnification.
Answer:
The image is formed at 0.44 m in front of the mirror
magnification (M) = 0.44
Explanation:
Applying, mirror formular
1/f = (1/u)+(1/v).................... Equation 1
Where f = Focal length of the convex mirror, u = object distance, v = image distance.
Using the real is positive convection,
From the question,
Given: f = -1.6/2 = -0.8 m( The focal length of a convex mirror is vitual), u = 1.0 m
Substitute these values into equation 1
-1/0.8 = (1/v)+(1/1)
Solve for v
1/v = 1.25+1
1/v = 2.25
v = 1/2.25
v = 0.44 m
Hence the image is formed at 0.44 m in front of the mirror
Magnification (M) = v/u
m = 0.44/1
m = 0.44
health ,population and environment education is for the enrichment of quality of life,justify the statement
Answer:
hey !! here is a short and sweet answer to your question
=quality of life is directly determined by health ,education ,and life expectacy
=health Is a type of thing that gives employment to the person working in firm
hope u understand
Explanation:
If we go on the top of the Mountain we will our weight increase or decrease?
Answer:
increase
Explanation:
guesshejwoowsnnsnakalalapqjhdjd
Answer:
our weight would decrease.
Explanation:
because of you burning all those calories and fat from hiking up the mountain.
HELPPPPPPPPPPP PLEASEEEEEEEEEEE
Complete this sentence. The solubility of a sample will ____________ when the size of the sample increases.
stay the same
decrease
increase
be unable to be determined
the answer is not decrease
The solubility of the sample will decrease
How would you find the resistance of a parallel circuit with n identical resistors?
9514 1404 393
Answer:
R/n
Explanation:
For a given voltage V across each resistor R, the current is V/R. Since there are n parallel paths, the total current is n(V/R). The effective resistance is ...
Reff = V/I = V/(nV/R)
Reff = R/n
If Cl− is the only anion in the solution, what is the Cl− concentration in milliequivalents per liter?
Answer:
155mEq/L Cl-
Explanation:
A Ringer’s solution contains the following concentrations of cations: 146 mEq/L of Na+, 5 mEq/L of K+, and 4 mEq/L of Ca2+.
As Cl- is the only counterion of those cations:
For Na, the molecule is NaCl and the mEq/L of Cl- = mEq of Na+. The Cl- of the first ion is 146mEq/L Cl-
For K+, The molecule is KCl, mEq Cl- = 5mEq/L Cl-
And, for Ca2+, The molecule is CaCl2 but the equivalents of Ca2+ = Equivalents of Cl- = 4mEq/L Cl-
The total concentration of Cl- are:
146 + 5 + 4 =
155mEq/L Cl-List out the fundamental and derived units
The boiling point of water is 1000 C at sea level. The boiling point of butane is -1.50C… If we leave liquid butane in a bowl on a table in a room where the temperature is 240C, butane will
A. evaporate.
B. condense.
C. freeze.
D. melt.
Answer: If we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.
Explanation:
A temperature at which the the liquid and gaseous phase of a substance of a substance are present in equilibrium with each other is called boiling point.
For example, the boiling point of butane is -1.5 degree Celsius.
This means that at a temperature above -1.5 degree Celsius, butane will exist is gaseous state. That is, at a temperature of 24 degree Celsius butane will evaporate.
Thus, we can conclude that if we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.
49. A block is pushed across a horizontal surface with a
coefficient of kinetic friction of 0.15 by applying a
150 N horizontal force.
(a) The block accelerates at the rate of 2.53 m/s2
Find the mass of the block.
(b) The block slides across a new surface while
experiencing the same applied force as before.
The block now moves with a constant speed.
What is the coefficient of kinetic friction between
the block and the new surface?
Answer:
(a) 37.5 kg
(b) 4
Explanation:
Force, F = 150 N
kinetic friction coefficient = 0.15
(a) acceleration, a = 2.53 m/s^2
According to the newton's second law
Net force = mass x acceleration
F - friction force = m a
150 - 0.15 x m g = m a
150 = m (2.53 + 0.15 x 9.8)
m = 37.5 kg
(b) As the block moves with the constant speed so the applied force becomes the friction force.
[tex]F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4[/tex]
Which symbol and unit of measurement are used for electric current?
symbol. A, unit: 1
symbol: C, unit: A
symbol l; unit C
symbol: 1; unitA
Answer: Symbol is I and unit A
Explanation: A represents Amperes
HOPE THIS HELPS!!!!!!!!
un litro de un gas es calentado a presión constante desde 20°C hasta 60°C que volumen final ocupará dicho gas?
Answer:
Final volume, V2 = 3 Litres
Explanation:
Given the following data;
Initial volume, V1 = 1 litre
Initial temperature, T1 = 20°C
Final temperature, T2 = 60°C
To find the final volume, we would use Charles' law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
V1/T1 = V2/T2
Making V2 as the subject formula, we have;
V1T2 = V2T1
V2 = (V1T2)/T1
Substituting into the formula, we have;
V2 = (1 * 60)/20
V2 = 60/20
Final volume, V2 = 3 Litres
The primary circuit of a transformer has a voltage of 80 V and 300 windings. The secondary circuit has a voltage of 240. How many windings are there in the secondary circuit? *
Answer:
900 windings
Explanation:
Applying,
Vs/Vp = Ns/Np............. Equation 1
Where Vs = Secondary voltage, Vp = primary voltage, Ns = Number of turns in the secondary circuit, Np = number of turns in the primary circuit
make Ns the subject of the equation
Ns = VsNp/Vp........... Equation 2
From the question,
Given: Vs = 240 V, Np = 300 windings, Vp = 80 V
Substitute these values into equation 2
Ns = (240×300)/80
Ns = 900 windings
what do you mean by supplementary quantities and its unit?
$ \large\boxed{ \sf \red{More ~Info :}}$
The units of supplementary quantities are dimensionless units.
[tex] \\ [/tex]
what is the effect of pressure on boiling and melting substance?
Answer:
The boiling point of liquids always increases when pressure is applied on a liquid. This is because the molecules of a liquid will need more energy to turn into a gaseous state when pressure is applied on that substance.
I have possess'd your grace of what I purpose:And by our holy Sabbath have I swornTo have the due and forfeit of my bond.If you deny it, let the danger lightUpon your charter and your city's freedom !You'll ask me, why I rather choose to haveA weight of carrion flesh than to receiveThree thousand ducats : I'll not answer that:But, say, it is my humour(1) Whom are these lines addressed to? What is the context in which theselines are spoken?(ii) What has Shylock sworn on oath ?
Answer:
1. These lines are addressed to Duke.
2. These lines show that Shylock is not willing to forgive the debt a merchant owes him, nor is he willing to justify why he demands that debt be paid, even if it seems cruel.
3. He swore by the Holy Sabbath, which is a holy day for him, who is a Jew. He swore he would get the debt money or a piece of the debtor's flesh.
Explanation:
The lines shown in the question above refer to "The Merchant of Venice" written by Shakespeare. In this story we are introduced to Antonio, a commercial who is very prejudiced against Jews, but when he needs money, he borrows from another merchant, Shylock, who is Jewish. Shylock agrees to lend money to Antonio, but determines the date that this money must be returned, in addition, Shylock states that he will lend the money if Antonio agrees that if this money is not paid by the specified date, Antonio will have to pay with half a kilo of flesh from his own body. Antonio agrees, but doesn't pay the money so Shylock goes after the flesh of Antonio's body and Duke tries to intervene because he thinks this is too cruel. At this point, Shylock speaks the lines shown in the question above, showing that he is not willing to change his mind.
Which labels are correct for the regions marked? a. X: Slower in gases than liquids Y: Faster in solids than gases Z: Velocity depends on medium b. X: Faster in gases than liquids Y: Slowest in solids Z: Faster in liquids than gases c. X: Slower in solids than liquids Y: Velocity depends on medium Z: Faster in liquids than gases d. X: Velocity depends on medium Y: Fastest in gases Z: Slower in liquids than solids
Answer:
a. X: Slower in gases than liquids Y: Faster in solids than gases Z: Velocity depends on medium.
Explanation:
Speed of sound is fastest in solids. Sound waves travel more quickly in solid, than of liquid and gases. Sound waves travel most slowest in gases. Speed of sound varies significantly and it depends upon medium it is travelling through. In more rigid medium sounds velocity will be faster.
The gravitational force acting on various masses is measured on different planets. Measured values for the forces acting on the corresponding masses are shown in the data table. Analyze the data and develop a method for comparing the gravitational field strengths on the different planets. Use your method to compare the gravitational field strengths, and report your conclusions.
A 20-N force acts on a 5-kg object at rest. How fast will
the object accelerate on a frictionless surface?
A. 15 m/s^2
B. 25 m/s^2
C. 4 m/s^2
D. 100 m/s^2
Answer:
C.
Explanation:
Force = Mass * Acceleration
So 20 = 5* Acceleration
4 = Acceleration
The acceleration of the object is 4 m/s².
To find the acceleration, the given values are:
Force = 20 N
Mass = 5 kg
Define acceleration.Definition:
As it was given as the values of Force and mass, here acceleration definition depends on the Newton's second law of motion.
Using the second law of motion, the force will be equal to the product of the mass and the acceleration.
As formula,
F = ma Newton
Here, to find acceleration,
a =f/ m
Substituting the values,
= 20 / 5
a = 4m/s².
So, the acceleration was 4 m/s². The Option C is the correct answer.
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Which statement should he place in the region marked X?
Explanation:
The answer is Electrons move between objects.
