Answer:
The decrease in decibels is 0.1 dB.
Explanation:
Let the intensity of one chorus is Io.
let the intensity of 1000 vocalist is dB.
The intensity of 1000 vocalist is 1000 Io.
[tex]dB = 10log\frac{1000Io}{Io}=30[/tex]..... (1)
let the intensity of 999 vocalist is dB'.
[tex]dB' = 10log\frac{999Io}{Io}=29.9[/tex]..... (2)
So, the change is
= dB - dB' = 30 - 29.9 = 0.1 dB
A train moves with a uniform velocity of 36km/hr 10sec. calculate the distance travelled
Given:-
Speed = 36 km/hr
converting speed into m/s
Speed = 36*5/18
Speed = 10 m/s
t = 10 sec
By using the Formula
Distance = Speed * time
D = 10*10
D = 100 m
Hope it helps....
1. Convert the following length into meters
a. 123.50mm
b. 560cm
c. 100dm
d. 125.89km
A boy throws a ball straight up with a speed of 21.5 m/s. The ball has a mass of 0.19 kg. How much gravitational potential energy will the ball have at the top of its flight? (Assume there is no air resistance.) A. 43.9 J B. 37.5 J C. 48.5 J D. 41.2 J
Answer:
Explanation:
The equation fo potential energy is PE = mgh, where m is the mass of the ball, g is the pull of gravity (constant at 9.8), and h is the max height of the ball. What we do not have here is that height. We need to first solve for it using one-dimensional equations. What we have to know above all else, is that the final velocity of an object at its max height is always 0. That allows us to use the equation
[tex]v_f=v_0+at[/tex] where vf is the final velocity and v0 is the initial velocity. We will find out how long it takes for the object to reach that max height first and then use that time to find out what that max height is. Baby steps here...
0 = 21.5 + (-9.8)t and
-21.5 = -9.8t so
t = 2.19 seconds (Keep in mind that if I used the rules correctly for sig fig's, the answer you SHOULD get is not one shown, so I had to adjust the sig fig's and break the rules. But you know what they say about rules...)
Now we will use that time to find out the max height of the object in the equation
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:
Δx = [tex]21.5(2.19)+\frac{1}{2}(-9.8)(2.19)^2[/tex] which simplifies down a bit to
Δx = 47.1 - 23.5 so
Δx = 23.6 meters.
Now we can plug that in to the PE equation to find the PE of the object:
PE = (.19)(9.8)(23.6) so
PE = 43.9 J
Which one will it be
Answer:
none
Explanation:
it's to high up to be affected by the gravity
What are the messing forces that would make the object be in equilibrium?
Answer:
A) 20 N, B) 20 N, & C) 8 N
Explanation:
For the object to be in equilibrium, the upward forces must be equal to the downward forces and the forward forces must be equal to the backward forces.
1. Determination of A and B.
Forward forces = Backward forces
A + 10 + B = 25 + 25
A + 10 + B = 50
Collect like terms
A + B = 50 – 10
A + B = 40
Assume A and B to be equal. Thus, A is 20 N and B is 20 N.
2. Determination of C
Upward forces = Downward forces
C + 112 = 20 + 100
C + 112 = 120
Collect like terms
C = 120 – 112
C = 8 N
Thus, for the object to be in equilibrium, A must be 20 N, B must be 20 N and C must be 8N.
A 1250-kg compact car is moving with velocity v1 =36.2i^+12.7j^m/s. It skids on a frictionless icy patch and collides with a 448-kg hay wagon moving with velocity v2=13.8i^+10.2j^m/s.
If the two stay together, what is their velocity?
Express your answer in meters per second in terms of i^ and j^. Use the 'unit vector' button to denote unit vectors in your answer.
Momentum is conserved, so the sum of the separate momenta of the car and wagon is equal to the momentum of the combined system:
(1250 kg) ((36.2 i + 12.7 j ) m/s) + (448 kg) ((13.8 i + 10.2 j ) m/s) = ((1250 + 448) kg) v
where v is the velocity of the system. Solve for v :
v = ((1250 kg) ((36.2 i + 12.7 j ) m/s) + (448 kg) ((13.8 i + 10.2 j ) m/s)) / (1698 kg)
v ≈ (30.3 i + 12.0 j ) m/s
how to reduce fluid friction
Answer:
By making the object sharp pointed
A surfactant with a Hydrophile-
Lipophile Balance (HLB) value of 18 is expected to function as a solubilizing agent
O False
O True
Answer:
Explanation:
True
The Best answer from the options is TRUE
A surfactant with a Hydrophile-lipophile Balance value of 18 is a solubilizing agent because a hydrophilic-lipophilic balance is used to measure the degree /level of hydrophilicness or liphophilicness of a Surfactant is at . and the
method used by the Hydrophile-lipophile balance to achieve this is by calculating the values for the different regions of the surfactant.
Hence a Surfactant with a hydrophile-lipophile Balance value of 18 is expected to function as a solubilizing agent.
Attached below is the HLB
Learn more : https://brainly.com/question/11338364
A block with length of 1.5m,width 1=1m,height=0.5m and mass 300kg.what is the pressure at the bottom surface of the block
Answer:
Find The area and calculate pressure.
Explanation:
What is energy?
Select one:
A force that must be exerted in order to accelerate an object.
A property that must be transferred to perform work.
A particle that can be absorbed to change momentum.
A system that can be rearranged in order to change its state.
Answer:
Energy is:
A property that must be transferred to perform work.
Answer:
EnergyExplanation:
A property that must be transferred to perform work .Hope it is helpful to you Stay safe healthy and happy ☺️A block of mass m is moved over a distance d. An applied force F is directed perpendicularly to the block’s displacement. How much work is done on the block by the force F?
zero
Explanation:
Work W is defined as
W = F•d = Fdcos(theta)
and it is a dot product of the force and displacement and theta is angle between F and d Since the force is perpendicular to d, angle is 90° thus cos90 = 0. Hence work is zero.
A pilot wishes to fly from Bayfield to Kitchener, a distance of 100 km on a bearing of 105°. The speed of the plane in still air is 240 km/h. A 20 km/h wind is blowing on a bearing of 210°.
Remembering that she must fly on a bearing of 105° relative to the ground (i.e. the resultant must be on that bearing), find (6 marks)
a) the heading she should take to reach her destination.
b) how long the trip will take.
A 8.37*10^-5 F capacitor has 2.15*10^-4 C of charge on its plates. How much energy is stored on the capacitor
Answer:
2.76*10^-4
Explanation:
Trust me :)
Using only astronomical data from the Appendix E in the textbook, calculate the speed of the planet Venus in its essentially circular orbit around the sun.
Venus = 4.87x10^24
Answer:
[tex]v=3.49\times 10^4\ m/s[/tex]
Explanation:
Given that,
Mass of Venus, [tex]M_V=4.87\times 10^{24}\ kg[/tex]
We know that,
Mass of Sun, [tex]M_s=1.98\times 10^{30}\ kg[/tex]
The distance between the center of Sun and the center of Venus is [tex]1.08\times 10^{11}\ m[/tex]
We need to find the peed of the planet Venus in its essentially circular orbit around the sun. using the formula,
[tex]v=\sqrt{\dfrac{GM_s}{r}}[/tex]
Put all the values,
[tex]v=\sqrt{\dfrac{6.67\times 10^{-11}\times 1.98\times 10^{30}}{1.08\times 10^{11}}}\\\\v=3.49\times 10^4\ m/s[/tex]
So, the speed of the planet venus is [tex]3.49\times 10^4\ m/s[/tex].
Sunsets are a deep red because A) tiny particles in the air are more efficient at scattering short wavelength light than they are at scattering long wavelength light. Hence, long wavelength light ends up coming directly towards you. B) most polluting gases and dust particles in the air are reddish in color and lend their color to that of the sky. C) air molecules absorb red light more efficiently than they do blue light because of their electron orbitals. D) air molecules absorb blue light more efficiently than they do red light because of their electron orbitals.
Answer:
i think its A
Answer:tiny particles in the air are more efficient at scattering short wavelength light than they are at scattering long
Explanation:
A 20-g bullet moving at 1000 m/s is fired through a 1kg block of wood emerging at a speed of 100m/s.what is the change in kinetic energy of the bullet
Answer:
D. 0.16 KJ
Explanation:
Given the following data;
Initial velocity, U = 1000 m/s
Mass of bullet, M1 = 20 g to kilograms = 20/1000 = 0.02 kg
Mass of block, M2 = 1 kg
Final velocity, V = 100 m/s
To find the change in kinetic energy;
First of all, we would determine the velocity after the collision by applying the law of conservation of momentum.
[tex] M_{1}U - M_{1}V = M_{2}V_{f} [/tex]
Substituting into the above formula, we have;
[tex] 0.02*1000 - 0.02*100 = 1*V_{f} [/tex]
[tex] 20 - 2 = V_{f} [/tex]
Vf = 18 m/s
Next, we would find the kinetic energy of block-bullet;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Substituting into the formula, we have;
[tex] K.E = \frac{1}{2}*1*18^{2}[/tex]
[tex] K.E = \frac{1}{2}*324 [/tex]
K.E = 162 Joules.
In Kilojoules;
K.E = 162/1000
K.E = 0.162 ≈ 0.16 KJ
Deciding on the narrative point of views mean that an author must choose
Answer:
from which perspective the story is being told to the reader
Explanation:
i.e. first person on through third person or narrated.
Answer:
Deciding on the narrative point of views mean that an author must choose who is telling the story.
Explanation:
A narrative point of view is when the narrator becomes the character of the story who also knows the emotions or feelings and thoughts of the character. The narrator can be the first person or can be the third person depending on the characters included in the story.
What is the magnitude of vector X?
Explanation:
by using Pythagoras theorem
h²=p²+b²
z²=Y²+x²
x²=75²-21²
x=√5184
x=72cm is the magnitude of vector X
hope it helps
stay safe healthy and happy.Mixed powders may be categorized as
Answer:
on flow properties and free-flowing and cohesive.
Explanation:
the power Free flowing powders do not cling together, as cohesive powders stick to each other and form that do not disperse well during mixing
a. A horse pulls a cart along a flat road. Consider the following four forces that arise in this situation.
1. the force of the horse pulling on the cart
2. the force of the cart pulling on the horse
3. the force of the horse pushing on the road
4. the force of the road pushing on the horse
b. Suppose that the horse and cart have started from rest; and as time goes on, their speed increases in the same direction. Which one of the following conclusions is correct concerning the magnitudes of the forces mentioned above?
1. Force 1 exceeds Force 2.
2. Force 2 is less than Force 3.
3. Force 2 exceeds Force 4.
4. Force 3 exceeds Force 4.
5. Forces 1 and 2 cannot have equal magnitudes.
Answer:
a) F₁ = F₂, F₃ = F₄, b) the correct answer is 3
Explanation:
a) In this exercise we have several action and reaction forces, which are characterized by having the same magnitude, but different direction and being applied to different bodies
Forces 1 and 2 are action and reaction forces F₁ = F₂
Forces 3 and 4 are action and reaction forces F₃ = F₄
as it indicates that the
b) how the car increases if speed implies that force 1> force3
F₁ > F₃
therefore the correct answer is 3
The cycle is a process that returns to its beginning, but it does not repeat
itself.
True
False
On page 14 of the call of the wild jack London, writes,in vague ways he remembered back to the youth of the breed ,this statement is example of
Answer:
On page 14 of the call of the wild jack London, writes,in vague ways he remembered back to the youth of the breed ,this statement is example of the racial unconscious. As a general rule, really great novels contain universal truths.
Explanation:
Hey mate dont worry! My answer is correct!!
Answer:
racial unconscious
Explanation:
took the test and it was correct
Which option is the best blackbody radiator?
A.
The Sun
B.
A red laser pointer
C.
A tennis ball
D.
Boiling water
Answer:
A. The Sun
Explanation:
The Sun is to be considered a perfect black body.
A string that is under 50.0N of tension has linear density 5.0g/m. A sinusoidal wave with amplitude 3.0cm and wavelength 2.0m travels along the string. What is the maximum speed of a particle on the string
Answer:
9.42 m/s
Explanation:
Applying,
V' = Aω.............. Equation 1
Where V' = maximum speed of the string, A = Amplitude of the wave, ω = angular velocity.
But,
ω = 2πf................. Equation 2
Where f = frequency, π = pie
And,
f = v/λ................ Equation 3
Where, λ = wave length, v = velocity
Also,
v = √(T/μ)................. Equation 4
Where T = Tension, μ = linear density.
From the question,
Given: T = 50.0 N, μ = 5.0 g/m = 0.005 kg/m
Substitute into equation 4
v = √(50/0.005)
v = √(10000)
v = 100 m/s
Also Given: λ = 2.0 m
Substitute into equation 3
f = 100/2
f = 50 Hz.
Substitute the value of f into equation 2
Where π = constant = 3.14
ω = 2(3.14)(50)
ω = 314 rad/s
Finally,
Given: A = 3.0 cm = 0.03 m
Substitute into equation 1
V' = 0.03(314)
V' = 9.42 m/s
What is the equivalent resistance of a circuit that contains two 50.0 0
resistors connected in series to a 12.0V battery?
Answer:
the correct answer is A :)
A hoop rolls with constant velocity and without sliding along level ground. Its rotational kinetic energy is:______a- half its translational kinetic energyb- the same as its translational kinetic energyc- twice its translational kinetic energyd- four times its translational kinetic energy
Answer:
The same as its translational KE.
The easy way to do this is to make up numbers and use them.
So, I'll say m=2 and r=3. I will also say v=3 .
Rot. Inertia of a hoop is mr^2. So the rot KE is: 1/2 (mr^2)(w^2)
note: (1/2*I*w^2)
Translational kinetic energy is basically normal KE, so 1/2(m)(v^2)
Now, lets plug our made up values in:
Rot Ke : 1/2 (9*2)(3/3) *note w = v/r
Tran Ke: 1/2(2)(9)
Rot Ke: 9
Tran Ke: 9
9=9, same.
Two thin conducting plates, each 56.0 cm on a side, are situated parallel to one another and 7.0 mm apart. If 10^-10 electrons are moved from one plate to the other, what is the electric field between the plates?
Answer:
[tex]E=576.5V/m[/tex]
Explanation:
From the question we are told that:
Length [tex]l=56.0cm=0.56m[/tex]
Distance apart [tex]d=7.0mm=0.007m[/tex]
Electron Transferred [tex]n=10^{-10}[/tex]
Therefore
Total Charge
Since Charge on each electron is
[tex]e=1.602*10^{-19}[/tex]
Therefore
[tex]T=1.602*10^{-19} *10^{10}[/tex]
[tex]T=1.602*10^{-9}[/tex]
Generally the equation for Charge density is mathematically given by
[tex]\rho=T/A[/tex]
Where
Area
[tex]A=0.56*0.56[/tex]
[tex]A=0.3136[/tex]
Therefore
[tex]\rho=1.602*10^{-9}/0.3136[/tex]
[tex]\rho=5.10*10^{-9}[/tex]
Generally the equation for Electric Field in the capacitor is mathematically given by
[tex]E=\frac{\rho}{e_0}[/tex]
[tex]E=\frac{5.10*10^{-9}}{8.85x10{-12}}[/tex]
[tex]E=576.5V/m[/tex]
According to Coulomb's law, if the separation between two particles of the same charge increases four times, the potential energy of the two particles:__________.
a. is one-sixteenth as high as it was before the separation.
b. is four times as high as it was before the distance separation.
c. is one-fourth as high as it was before the separation.
d. does not change.
Answer:
c. V = k Q1 * Q2 / R1 potential energy of Q1 and Q2 separated by R
V2 / V1 = (R1 / R2) = 1/4
V2 = V1 / 4
According to Coulomb's law, if the separation between two particles of the same charge increases four times, the potential energy of the two particles is is one-fourth as high as it was before the separation. The correct option is c.
What is Coulomb's law?Coulomb's law states that the force of attraction or repulsion among both two charged bodies is directly related to the sum of their charges and inversely proportional to the square of the distance between them.
Coulomb force is the attraction or repulsion of particles or objects due to their electric charge. It is also known as electrostatic force or Coulomb interaction.
It denotes the electric force's inverse square dependence. It can also be used to accurately provide relatively simple derivations of Gauss' law for general cases.
Coulomb's law states that if the separation between two particles of the same charge increases four times, the potential energy of the two particles is one-fourth of what it was before the separation.
Thus, the correct option is c.
For more details regarding Coulomb's law, visit:
https://brainly.com/question/506926
#SPJ2
instrument used in measurement Amount of substance
Answer:
For liquids: A measuring cylinder is used.
For solid: Over flow can is used
Answer:
i think a measuring cylinder
The image shows the right-hand rule being used for a current-carrying wire.
An illustration with a right hand with fingers curled and thumb pointed up.
Which statement describes what the hand shows?
When the current flows down the wire, the magnetic field flows out on the left side of the wire and in on the right side of the wire.
When the current flows up the wire, the magnetic field flows out on the left side of the wire and in on the right side of the wire.
When the current flows down the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
When the current flows up the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
Answer:
The answer is (D): When the current flows up the wire, the magnetic field flows in on the left side of the wire and out on the right side of the wire.
Explanation:
