Answer:
β = 114 db
Explanation:
The intensity of sound in decibles is
β = 10 log [tex]\frac{I}{I_{o}}[/tex]
in most cases Io is the hearing threshold 1 10-12 W / cm²
let's calculate the intensity of each instrument
I / I₀ = 10 (β / 10)
I = I₀ 10 (β / 10)
trumpet
I1 = 1 10⁻¹² 10 (94/10)
I1 = 2.51 10⁻³ / cm²
Thrombus
I2 = 1 10⁻¹² 10 (107/10)
I2 = 5.01 10-2 W / cm²
low
I3 =1 1-12 (113/10) W/cm²
I3 = 1,995 10-1 W / cm²
when we place the three instruments together their sounds reinforce
I_total = I₁ + I₂ + I₃
I_ttoal = 2.51 10-3 + 5.01 10-2 + 1.995 10-1
I_total = 0.00251 + 0.0501 + 0.1995
I_total = 0.25211 W / cm²
let's bring this amount to the SI system
β = 10 log (0.25211 / 1 10⁻¹²)
β = 114 db
What is the lithosphere?
A. the outer layer of the Earth's crust
B. the inner core
C. the middle portion of the mantle
D. the outer core
Answer:
a. outer layer
Explanation:
lithosphere is right underneath the continental and ocean crust. it is approximately 100 km in deep and it is a brittle layer. It is broken into tectonic plates.
the inner core is located at the very center and its full of iron and nickel (so its not B)
on top of that is the outer core which is liquid (not D)
the middle portion of the mantle is the asthenosphere and mesosphere. they are right beneath the lithosphere. (not C)
so the best answer is A
Based on its location on the periodic table, which metal is likely to be less reactive than both strontium and sodium?
magnesium (Mg)
barium (Ba)
cesium (Cs)
rubidium (Rb)
Answer:
Magnesium is the correct answer
Explanation:
It is magnesium because as we move down the periodic table group, atomic sizes increase which is as a result of lesser forces of attraction between nucleus and valence of an atom which makes the atom to be prone to leave as electrons so easily, elements become more reactive.
But as we move along the period , atomic sizes decrease because there is a more force of attraction between nucleus of an atom and it valence electrons making it less reactive just as the case in magnesium. Other elements are more reactive than it across the group.
Answer:
Magnesium
Explanation: Correct on edge!
Hope this Helps! :)
A small, 300 g cart is moving at 1.10 m/s on an air track when it collides with a larger, 4.00 kg cart at rest. After the collision, the small cart recoils at 0.890 m/s. What is the speed of the large cart after the collision (answer in m/s please)?
Answer:
0.0158m/s
Explanation:
Using the law of conservation of energy which states that the sum of momentum before collision is equal to the sum after collision. It is expressed mathematically as;
m1u1 + m2u2 = m1v1 + m2v1
m1 and m2 are the masses of the object
u1 and u2 are the initial velocities
v1 and v2 are the final velocities
Given
m1 = 300g = 0.3kg
u1 = 1.10m/s
m2 = 4.00kg
u2 = 0m/s (at rest)
v1 = 0.890
v2 = ?
Substitute the given values into the formula;
0.3(1.10) + 0 = 0.3(0.89) + 4v2
0.33 = 0.267 + 4v2
0.33-0.267 = 4v2
0.063 = 4v2
v2 = 0.063/4
v2 = 0.0158m/s
Hence the speed of the large cart after the collision is 0.0158m/s
According to the question:
Mass,
[tex]m_1 = 300 \ g = 0.3 \ kg[/tex][tex]m_2 = 4.00 \ kg[/tex]Final velocity,
[tex]u_1 = 1.10 \ m/s[/tex][tex]u_2 = 0 \ m/s[/tex]Initial velocity,
[tex]v_1 = 0.890 \ m/s[/tex][tex]v_2 = \ ?[/tex]By using the law of conservation, we get
→ [tex]m_1 u_1 +m_2 u_2 =m_1 v_1 +m_2 v_1[/tex]
By substituting the values, we get
→ [tex]0.3(1.10)+0 = 0.3(0.89)+4v_2[/tex]
→ [tex]0.33=0.267+4 v_2[/tex]
[tex]0.33-0.267 = 4 v_2[/tex]
[tex]0.063 =4v_2[/tex]
[tex]v_2 = \frac{0.063}{4}[/tex]
[tex]= 0.0158 \ m/s[/tex]
Thus the response above is appropriate.
Learn more about speed here:
https://brainly.com/question/14478313
A herdsman yelling out to a fellow herdsman heard his voice reflected by a cliff 4s later.What is
the velocity of sound in air if the cliff is 680m away
Answer:
v = 340 m/s
Explanation:
Given that,
A herdsman yelling out to a fellow herdsman heard his voice reflected by a cliff 4s later.
The cliff is 680 m away
We need to find the velocity of sound in air.
Velocity = distance/time
Distance = 2 × 680 = 1360 m
[tex]v=\dfrac{1360\ m}{4\ s}\\\\=340\ m/s[/tex]
So, the velocity of sound in air is 340 m/s.
How long( in hours, will it take for 500 000 C of charge to flow through a diode if it requires
0.05 Amp to operate it.
Answer:
277.78 hours
Explanation:
The formula for calculating the amount of charge is expressed as;
Q = It
I is the current
t is the time
Given
I =0.05A
Q = 50,000C
Required
Time t
Recall that: Q = It
t = Q/I
t = 50,000/0.05
t = 1,000,000secs
Convert to hours
1,000,000secs = 1,000,000/3600
1,000,000secs = 277.78 hours
Hence it will take 277.78 hours for the charge to flow through the diode
A ray moving in water at 55.5 deg
enters plastic, where it bends to
48.7 deg. What is the index of
refraction for the plastic?
( water n = 1.33, Air n = 1.00 )
Answer:
Refractive index of the plastic = 1.46
Explanation:
By Snell's law,
[tex]\frac{\text{sin}\theta _{2} }{\text{sin}\theta _{1}}=\frac{n_1}{n_2}[/tex]
Here, [tex]\theta _1[/tex] = Angle of incidence in medium 1 (Plastic)
[tex]\theta_2[/tex] = Angle of refraction in medium 2 (Water)
[tex]n_1[/tex] = Refractive index of medium 1 (Plastic)
[tex]n_2[/tex] = Refractive index of medium 2 (Water)
By substituting values in the formula,
[tex]\frac{\text{sin}(48.7)}{\text{sin}(55.5)}=\frac{1.33}{n_2}[/tex]
[tex]n_2=\frac{1.33\times \text{sin}(55.5)}{\text{sin}(48.7)}[/tex]
= 1.46
Therefore, refractive index of the plastic = 1.46
Give reason:
a) In 'coin on card' experiment a smooth card is used.
Answer:
Please mark as brainliest!!
Explanation:
In coin card experiment smooth card is used so that the card can slide easily from glass.
Answer:
In coin card experiment smooth card is used so that the card can slide easily from glass.
two spheres A and B are projected off the edge of a 1.0 m high table with the same horizontal velocity . sphere A has a mass of 20.g and sphere B has a mass of 10.g.
If both spheres leave the edge of the table at the same instant, sphere A will land
a. at some time after sphere B.
b. at the same time as sphere B.
c. at some time before sphere B.
d. There is not enough information to decide.
Answer:
A lands first becuase its heavier
A 200 g air-track glider is attached to a spring. The glider is pushed 10.0 cm against the spring, then released. A student with a stopwatch finds that 10 oscillating take 12.0 s. What is the spring constant?
Answer:
5.5N/m
Explanation:
Calculation for What is the spring constant
First step is to calculate the time period
T = 12 second/10
T = 1.2 second
Now let calculate the spring constant using this formula
k=4π²m/T²
Where,
m=0.2kg
T=1.2second
k represent spring constant=?
Let plug in the formula
k=4π²×0.2kg/(1.2)²
k=39.48×0.2kg/1.44
k=7.90/1.44
k=5.48N/m
k=5.5N/m ( Approximately)
Therefore the spring constant will be 5.5N/m
A race car starts from rest and accelerates down a track at a rate of 3.0 m/s2
How fast is the car moving after 10 seconds?
30 m/s
Explanation:We are given:
Initial Velocity (u) = 0 m/s
Acceleration of the Car (a) = 3 m/s²
Time Interval (t) = 10 seconds
Speed of the Car After 10 seconds:
From the First equation of motion:
v = u + at
replacing the given values
v = 0 + (3)(10)
v = 30 m/s
Hence, the car is moving at a velocity of 30 m/s after 10 seconds
(kg)
The table shows the relationship between the masses of two objects, the distance between the
two objects, and the gravitational force between the objects
Mass
of Object 1 Mass of Object 2 Distance between Gravitational
(kg)
Objects 1 and 2 Force between
(m)
Objects 1 and 2
(N)
1
16
2G
2
1 G
3
3
9 G
9
3
3
3G
1
2
1
6. Which conclusion is supported by the data in the table? (1 point)
An increase in the mass of an object causes the same decrease in the gravitational force
An increase in the distance between the objects causes the same decrease in the gravitational force
An increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass.
An increase in the mass causes a greater change in the gravitational force than the same increase in the distance between the objects
Answer:
(C) an increase in tue distance between the ibject causes a greater change in the gravitational force than the same increase in mass
Hope this helps
Answer:
C: An increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass.
Explanation:
it's C on edge! hope this helps!!~ (❁´▽`❁)*✲ﾟ*
What is the centripetal force necessary to keep a 0.4 kg object rotating in a circular path
of radius 3m?
Answer:
ertdhrsg
Explanation:
gesrgsg
The image shows a diagram explaining a concept.
Which concept does the diagram show?
A. tempature
B. Altitude
C. air density
D. air pressure
Answer:
D.
Explanation
Air pressure.
Answer:air pressure
Explanation:
the surface of objects in contact are not completely smooth true or false
Answer:
true objects in contact are not completely smooth
The reason why you should always exercise your abdominal during an exercise session is :
(A) because you will be fully warmed up
(B) you can focus on this muscle better
(C) because is the abdominal muscle is needed in all exercises during a workout
(D) because most people do it that way
(E) it does not really matter if you exercise the abdominal first or last
12) Consider two identical bricks, each of dimensions 20.0 cm x 10.0 cm x 6.0 cm. One is stacked
on the other, and the combination is then placed so that they project out over the edge of a
table. What is the maximum distance that the end of the top brick can extend beyond the table
edge without toppling?
A) 7.5 cm
B) 10 cm
C) 12.5 cm
D) 15 cm
Answer:
7.5
Explanation:
an electric iron draws a current of 5a when connected to a 250v supply. calculate the energy used buy the iron if it's used for 10 minutes
Answer:
The energy used by the iron is 0.2083 KWH.
Explanation:
Electric Energy
The energy consumed by an electrical appliance is given by:
E = P.t
Where:
P = Power consumed
t = Time the appliance is connected to the power supply
The power can be calculated as a function of the voltage V and the current I:
P = V.I
Therefore, the energy is:
E = V.I.t
The electric iron draws a current of I=5 A when connected to a V=250 V supply for t=10 minutes. The time must be expressed in hours, thus t=10/60=0.167 hours.
Thus, the energy is:
E = 250 V * 5 A * 0.167 H
E = 208.33 WH
Converting to KWH:
E = 208.33/1000 = 0.2083 KWH
The energy used by the iron is 0.2083 KWH
Which best describes the law of conservation of mass?
O The coefficients in front of the chemicals in the reactants should be based on the physical state of the products,
O Products in the form of gases are not considered a part of the total mass change from reactants to products
O When reactants contain both a solid and a liquid, the solid counts toward the overall mass and the liquid does not
O The mass of the reactants and products is equal and is not dependent on the physical state of the substances.
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
52. Serves as an air passageway
a. Oropharynx
c. Nasopharynx
b. Laryngopharynx
d. Larynopharynx
Answer:
Nasopharynx
Explanation:
The nasopharynx is posterior to the nasal cavity and serves only as a passageway for air.
Find the total charge of a system consists 2X10^4 electrons.
ANSWER: The first thing to learn is how to convert numbers back and forth between scientific notation and ordinary decimal notation. The expression "10n", where n is a whole number, simply means "10 raised to the nth power," or in other words, a number gotten by using 10 as a factor n times:
105 = 10 x 10 x 10 x 10 x 10 = 100,000 (5 zeros)
108 = 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 100,000,000 (8 zeros)
Notice that the number of zeros in the ordinary decimal expression is exactly equal to the power to which 10 is raised.
If the number is expressed in words, first write it down as an ordinary decimal number and then convert. Thus, "ten million" becomes 10,000,000. There are seven zeros, so in powers of ten notation ten million is written 107.
A number which is some power of 1/10 can also be expressed easily in scientific notation. By definition,
1/10 = 10-1 ("ten to the minus one power")
More generally, the expression "10-n" (where n is a whole number) means ( 1/10 )n. Thus
10-3 = ( 1 / 10 )3 = 1 / ( 10 x 10 x 10) = 1/1000
10-8 = ( 1 / 10 )8 = 1/100,000,000
Scientific notation was invented to help scientists (and science students!)deal with very large and very small numbers, without getting lost in all the zeros. Now answer the following on a separate sheet of paper and check your answers by clicking on "Answers":
Explanation:
. A pendulum of length l = 9.8 m hangs in equilibrium and is then given velocity
v
=0.2
m/s at its lowest point. What is the amplitude of the subsequent oscillation?
Answer:
the amplitude of the sequence oscillation=
ASO = length × velocity
= 9.8 × 0.2 = 19.6
ASO = 19.6
The wavelength of a water wave is 54 m. It has a frequency of 0.03 Hz. What is the velocity of the wave?
Answer:
1.62 m/s
Explanation:
Wavelength of the water wave= 54 m
The frequency is 0.03 Hz
Therefore the velocity can be calculated as follows
Velocity= frequency × wavelength
= 0.03 × 54
= 1.62 m/s
Ishan is testing materials to see whether they will stick to a magnet. How can
he use his imagination in this experiment?
OA. To think of different materials to test
OB. To carefully record the results in a chart
O C. To do the test the same way each time
O D. To remember which materials are magnetic
Answer:
The Answer is A "To think of different materials to test"
Explanation:
APE X
Multiply.
(2x + 4)(x - 4)
Answer:
(2x + 4)(x - 4)=2x^2-4x-16
Using the law of conservation of energy, what is the kinetic energy at e?
Answer:
Send the pic so I can see
What's a Weber?
in electromagnetism
Answer:
In physics, the weber is the SI derived unit of magnetic flux. A flux density of one Wb/m2 (one weber per square metre) is one tesla.
Hope it helps !
Answer:
Weber unit of magnetic flux in the international system of units (SI), defined as the amount flux that, linking an electrical circuit of one turn (one loop of wire) , produces in it an electromotive force of one volt as the flux is reduced to zero as a uniform rate in one second .
it was named in honour of the 19th century German physicist Wilhelm Eduard Weber
A car is moving at 25.5 m/s when it accelerates at 1.94 m/s^2 for 2.3 s. What is the car's final speed? (Keep in mind direction and round to 2 decimals)
Answer:
29.96m/s
Explanation:
Given parameters:
Initial speed = 25.5m/s
Acceleration = 1.94m/s²
Time = 2.3s
Unknown:
Final speed of the car = ?
Solution:
To solve this problem, we are going to apply the right motion equation:
v = u + at
v is the final speed
u is the initial speed
a is the acceleration
t is the time taken
Now insert the parameters and solve;
v = 25.5 + (1.94 x 2.3) = 29.96m/s
what are the very small particles that make up matter
Answer:
The very small particles that make up matter are I) Atoms
Matter - Anything that have mass and occupies space is called matter . it is made up of atoms and molecules
Atoms - The smallest part of matter is called atom.
Molecule - Group of atoms combine together to form a molecule.
More to know - Atom is made up of even smaller particles called neutron, proton and electron. Electron moves around nucleus ( nucleus is made up of neutron and proton) Different types of atom combine and form molecule ( Nitrogen dioxide No2 has 1 atom of nitrogen and 2 atoms of oxygen)two asteroids crashed the crash caused both asteroids to change speeds scientist want to use the change
Answer:
The force each one experienced
Explanation:
Hope this helps :)
A child of mass m is at the edge of a merry-go-round of diameter d. When the merry-go-round is rotating with angular acceleration α, the torque on the child is τ. The child moves to a position half way between the center and edge of the merry-go-round, and the angular acceleration increases to 2α. The torque on the child is now
Answer:
The torque on the child is now the same, τ.
Explanation:
It can be showed that the external torque applied by a net force on a rigid body, is equal to the product of the moment of inertia of the body with respect to the axis of rotation, times the angular acceleration.In this case, as the movement of the child doesn't create an external torque, the torque must remain the same.The moment of inertia is the sum of the moment of inertia of the merry-go-round (the same that for a solid disk) plus the product of the mass of the child times the square of the distance to the center.When the child is standing at the edge of the merry-go-round, the moment of inertia is as follows:[tex]I_{to} = I_{d} + m*r^{2} = m*\frac{r^{2}}{2} + m*r^{2} = \frac{3}{2}* m*r^{2} (1)[/tex]
So, τ = 3/2*m*r²*α (2)When the child moves to a position half way between the center and the edge of the merry-go-round, the moment of inertia of the child decreases, as the distance to the center is less than before, as follows:[tex]I_{t} = I_{d} + m*\frac{r^{2}}{4} = m*\frac{r^{2}}{2} + m*\frac{r^{2}}{4} = \frac{3}{4}* m*r^{2} (3)[/tex]
Since the angular acceleration increases from α to 2*α, we can write the torque expression as follows:τ = 3/4*m*r² * (2α) = 3/2*m*r²
same result than in (2), so the torque remains the same.