Answer:
1 x 10 -10 whisper at 1m distance.
Explanation:
Properly fitted ear plugs an reduce noise form 15-30db. Although they are better for low frequencyAnswer:
The change in intensity is 63%.
Explanation:
intensity level = 18 db
Let the intensity is I.
Io = 10^(-12) W/m^2
Use the formula of intensity
[tex]dB = 10 log\left ( \frac{I}{Io} \right )\\\\18 = 10 log\left ( \frac{I}{Io} \right )\\\\1.8 = log\left ( \frac{I}{Io} \right )\\\\\left ( \frac{I}{Io} \right )=63.1[/tex]
So, the change in intensity is 63%.
John walked a distance of 900 meters in 10 minutes what was his average speed in kilomerters per hour
Answer:
5.4
Explanation:
900/10=90 and 90(60)=5400 meters. 5400/100=5.4
A ball of mass 1.0 kg is rolling due west at 30 m/s. A second ball of mass 2.0 kg moving due north at 6.0 m/s collides with the first ball and they stick together. What is the magnitude of the momentum of the two-ball system immediately after collision
Answer:
the magnitude of the momentum of the two-ball system immediately after collision is 32.31 kg.m/s
Explanation:
Given;
mass of the first ball, m₁ = 1.0 kg
mass of the second ball, m₂ = 2.0 kg
initial velocity of the first ball, v₁ = 30 m/s due west
initial velocity of the second ball, v₂ = 6 m/s due north
From the principle of conservation of linear momentum;
the total momentum before collision = total momentum after collision
The westward momentum of the first ball, = m₁v₁ = 1 x 30 = 30 kg.m/s
The northward momentum of the second ball = m₂v₂ = 2 x 6 = 12 kg.m/s
The resultant momentum of the two balls;
R² = 30² + 12²
R² = 1044
R = √1044
R = 32.31 kg.m/s
Therefore, the magnitude of the momentum of the two-ball system immediately after collision is 32.31 kg.m/s
Which nucleus completes the following equation?
Please ignore the answer I chose, it might be wrong
Answer:
D. [tex]^{39}_{18} Ar[/tex]
Explanation:
The given nuclear equation is the beta decay of chorine in which an electron, known as a beta particle, is given off from within the nucleus due to the breakdown of a neutron within the nucleus into a proton and a beta particle, such that the atomic number is increased by 1 from 17 to 18, which is the atomic number or argon, Ar, as follows;
[tex]^{39}_{17}Cl \ \rightarrow \ ^0_{-1} e + \ ^{39}_{18} Ar[/tex]
Can acceleration and velocity be equal vectors?
Answer:
Velocity is the rate of change of position with respect to time, whereas acceleration is the rate of change of velocity. Both are vector quantities (and so also have a specified direction), but the units of velocity are meters per second while the units of acceleration are meters per second squared.
explain how force and surface area affect the applied pressure.
Answer:
force and surface area are two factors affecting pressure on solids
more the force you apply, more will be the pressure
pressure and force are directly proportional meaning if Force is greater, pressure will also be greater
more the surface area of the solid less will be the pressure
surface area and pressure are inversely proportional meaning if surface are is big, pressure will be less, surface area small, pressure will be greater
Answer and Explanation:
We have a basic equation: Pressure = Force/Area.
So for example:
Increase pressure - increase the force or reduce the area the force acts on.
Decrease pressure - decrease the force, or increase the area the force acts on
The force per unit area is pressure. The force on the object is spread over the surface area. The area where the force is applied is divided by the equation for pressure.
Cheers,
Does water exist on Mars? Explain your answer. Why didn't Jupiter become a star during the early.
Answer:
yes water was discovered in mars
Guys please help this is very important it would be greatly appreciated if you would add the work. Thank you !!
Answer:
enjoy
Explanation:
The number of time a cricket chirps in a minute is a function of the temperature in the formula: n=4t-160, where n=number of times a cricket chirps a minute and t=temperature in farenheit. You can use the temperature t=(1/4)n+40 to estimate the temperature based on the number of chirps per minute.
y’all know what to do… please help
Answer:
A. It increased gradually as the reaction progressed.
Answer: A it increased gradually
as the reaction progressed
What are three differences and similarities between a Vernier Calipers and a Micrometer? (please leave a good answer)
Answer:
Explanation:
Vernier scale
Mathematical tool
A vernier scale, named after Pierre Vernier, is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation; thereby increasing resolution and reducing measurement uncertainty by using vernier acuity to reduce human estimation error. Wikipedia
Purpose: Measuring more precisely than could be done unaided when reading a uniformly divided straight or circular measurement scale
Creator: Pierre Vernier
Year invented: 1631
..............................................................................................................................................................................................................................................................................................
A micrometer is a measuring instrument that can make extraordinarily precise measurements. Most micrometers are designed to measure within one one-thousandth of an inch! That's a close fit. Exact measurements like this are necessary when even the smallest of space between objects can cause problems or difficulties.
Micrometer
Mathematical tool
A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw widely used for accurate measurement of components in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers. Wikipedia
Operation supported: Component measurement
Purpose: Precision measurement of a component
Variant: Digital mics, Bench micrometer, Limit mics, Digit mics, MORE
Component: Screw, Spindle, Ratchet stop, Anvil, Frame, Barrel, Thimble lock, Thimble
Application: Mechanical Engineering, Machining
The distance a cart moves down a track (from rest) is proportional to the time squared. How far would a cart move down a track (from rest) in two seconds if it moves (from rest) a distance of 20 cm in one second?
A) 5 cm B) 10 cm C) 20 cm D) 40 cm E) 80 cm
A car move down a track a distance of 80 cm
Letter E 80 cm
Proportional
if the distance is proportional to the time square we can express such condition writing
d = k*t² (1)
where d is the distance t is the time and k is the constant of proportionality.
Now we must considerer that if the cart moves a distance of 20 cm in one second then by substitution in equation (1)
20 = k * (t)² ⇒ 20 = k*1 then k = 20
The proportionality constant is K = 20
To determine how far the cart move down in 2 seconds, again by substitution in equation (1) ( but now knowing k )
d = 20*(2)²
d = 20*4
d = 80 cm
After release of jet, energy is lost by the engine. How principle of conservation of energy is obeyed in this condition.
Answer:
The principle of conservation of energy states that in a closed system, the energy can neither be created nor destroyed between interacting particles and remains constant or transformed from one form to another
In the jet engine, the release of jet changes the number of interacting particles in the engine, and given that energy cannot be created in the instantaneously closed system of the engine, energy is carried away and therefore lost by particles in the jet exhaust
The conservation of energy principle is therefore obeyed in the condition in which the jet engine losses energy by the release of jet
Explanation:
you now barbecue is hot, but have you ever thought about the methods of heat transfer related to barbecue?
a) at your barbecue party, what would be an example of heat by conduction?
b) at your barbecue party where would heat be transferred b convection?
c) there is also radiation from the barbecue. where would you best feel this?
d) in some grill oven you put your meat under the heating element your meat is grilled by the heat coming from above. it will take longer to cook this meat than a similar piece on the barbecue can you explain this?
Answer:
Explanation:
There are three modes of heat transfer.
1. Conduction: It is the mode of heat transfer when the object is in contact with hot body and gradually the heat transfer from the hot end to the cold end.
2. Convection: It is the mode of heat transfer in which the molecules gets heated and moves up and the cold molecules comes down and the process continues till the entire liquid or gas is at same temperature.
3. Radiation: It is the process of heat transfer in which the heat is transferred in the form of heat waves.
(a) When the cook pot is placed on flame, it is the example of conduction.
(b) When the liquid is placed on the flame in a container, the liquid gets heated by the mode of convection.
(c) We feel heat as we stand near the flame so it is the example of radiation.
(d) because the heat is trapped so it becomes hot in lesser time.
A 5.41 kg ball is attached to the top of a vertical pole with a 2.37 m length of massless string. The ball is struck, causing it to revolve around the pole at a speed of 4.75 m/s in a horizontal circle with the string remaining taut. Calculate the angle θ, between 0∘ and 90∘, that the string makes with the pole. Use g=9.81 m/s2.
Answer:
θ = 66º
Explanation:
This exercise of Newton's second law must be solved in part, let's start by finding the slowing down acceleration of the ball
a = v² / r
the radius of the circle is
sin θ = r / L
r = L sin θ
we substitute
a = v² /L sin θ
now let's write Newton's second law
vertical axis
T_y -W = 0
T_y = W
radial axis
Tₓ = m a (1)
let's use trigonometry for the components of the string tension
cos θ = T_y / T
sin θ = Tₓ / T
Tₓ = T sin θ
we substitute in 1
T sin θ = [tex]\frac{m \ v^2}{L \ sin \theta}[/tex]
T L sin² θ = m v²
we write our system of equations
T cos θ = m g
T L sin ² tea = m v²
we divide the two equations
L [tex]\frac{sin^2 \theta}{cos \theta}[/tex] = v² / g
(1 -cos²)/ cos θ = [tex]\frac{v^2 }{g \ L}[/tex]
1 - cos² θ = [tex]\frac{4.75^2}{9.81 \ 2.37}[/tex] cos θ
cos² θ + 0.97044 cos θ -1 = 0
we change variable cos θ = x
x² + 0.97044 x - 1 =0
x= [tex]\frac{-0.97 \pm \sqrt{0.97^2 - 4 1} }{2}[/tex]
since the square root is imaginary there is no real solution to the problem, suppose that the radius is 1 m r = 1 m
T sin θ = [tex]\frac{m \ v^2}{ r}[/tex]
T cos θ = m g
resolved
tan θ = [tex]\frac{v^2}{ r g}[/tex]
θ = tan⁻¹ ( 4.75²/ 1 9.81)
θ = 66º
Un auto se desplaza por una carretera recta a una velocidad de 85 km/h. Al cabo de 2 horas, ¿qué distancia habrá recorrido, en metros?
Answer:
Distancia, D = 170,000 metros
Explanation:
Dados los siguientes datos;
Velocidad = 85 km/h Tiempo = 2 horasPara encontrar la distancia recorrida, en metros;
Matemáticamente, la distancia recorrida por un objeto se calcula mediante la fórmula;
Distancia = velocidad * tiempo
Sustituyendo los valores en la fórmula, tenemos;
Distancia = 85 * 2
Distancia = 170 kilómetros
A continuación, convertiríamos el valor en kilómetros a metros;
Conversión:
1 kilómetros = 1000 metros
170 kilómetros = D metros
Multiplicación cruzada, tenemos;
D = 170 * 1000
D = 170,000 metros
Por lo tanto, habría viajado 170,000 metros después de 2 horas.
How can you say gravitational force is a field force
Answer:
because gravity pulled us in the land if there is no gravitational force there will not be field force too
Explanation:
hope it's will help you
Difference between gravitational force and frictional
Explanation:
gravitational force or gravity is the force of attraction between objects that have mass.
frictional force is the forec that opposes motion (movement) when two surface are in contact. (acts in the opposite direction of motion)
so to sum it up,
- gravtional force is the force of attraction between objects that have mass.
- objects on the earth have weight because of gravitational force between them and the earth.
frictional force
- oppose motion
- slow down and stop moving objects and;
- produce heat
hope it helps :)
which of the following containing same amount of boiling hot water is likely to cool first and why? a. a breaker whose surface is covered with aluminum foil b. a breaker whose surface is painted black
The pressure at the ice point for a constant-volume gas thermometer is 4.81 x 10^4Pa.
While that at the steam point is 6.48 x 10^4 Pa.
What pressure would the thermometer indicate at 50°c?
Answer:
0 deg C = 4.81E4 pressure at 0 deg
100 deg C = 6.48E4 pressure at steam point
100 deg C - 50 deg C = (6.48 - 4.81) * 10^4 = 1.67E4 Pa
50 deg C = 50 / 100 * 1.67E4 + 4.81E4 = 5.65E4 Pa Just the halfway point between the two given pressures
Reference frame definitely changes when also changes
state the term used to describe the turning force exerted by the man pushing down on a lever to lift one end of a heavy log
The term used to describe the turning force exerted when pushing an object is effort.
What is effort?The is the input force or force applied at one point of a lever in order to overcome a load.
The relationship between effort, load and mechanical advantage of a lever is given as;
M.A = L/E
where;
M.A is mechanical advantageL is the loadE is the applied force or effortThus, the term used to describe the turning force exerted when pushing an object is effort.
Learn more about effort here: https://brainly.com/question/24237657
Which are characteristics of a prokaryotic cell? Select three options.
O contains DNA
O lacks DNA
O contains ribosomes
O lacks ribosomes
O contains a nucleus
O lacks a nucleus
I NEED THIS QUICKLY
Answer:
A. Contains DNA
C. Contains ribosomes
F. Lacks a nucleus
Explanation:
An iron weight, suspended by a string, is motionless. The tension
in the string is 4.75 newtons. What is the mass of the iron
weight?
Answer:
Explanation:
If the mass hangs at the end of the string and the string can support the mass and doesn't break, and the mass hangs still, that means that the tension in the string is equal to the downward pull of the mass. However, we are given the tension in Newtons and the mass needs to be in kg. So we use the equation for weight:
w = mg where w, the weight, is the same as the tension in the string. Gravity is always 9.8 in the metric system:
4.75 = m(9.8) so
m = .48 kg
Answer:
Answer: A
0.485 Kg
Explanation:
If the half-life of a decaying isotope is 10 years, which statement is true after
10 years?
Answer:
no is the most expensive but u have
1.Convert 340 cm into m *(answer=0.34m)
2.What is the weight of potatoes of mass 75kg on the surface of the earth? *(ans=735 N)
[g=9.8 m/s^2
[g=9.8 m/s^2]
3.The weight of body is 420 N.Calculate its mass. *(42.857 kg)*
Answers are all given so i just need the process please (i will mark you brainliest please..
Answer:
1.for the first one 100centimeters make 1 meter therefore
100cm-1m
340cm-x
340/100
=3.4
the answer is supposed to be 3.4, maybe there's a mistake with the question or the answer
2.the weight of a body is given by the formula
mass×gravity,in this case the mass is 75kg and the gravity is 9.8
weight=75×9.8
=735N
3.for this one the mass of a body is given by the formula
mass=weight/gravity
=420/9.8
=42.8kg
I hope this helps
A skipper on a boat notices wave crests passing his anchor chain every 5.6 s . He estimates the distance between wave crests to be 16 m . He also correctly estimates the speed of the waves. Find this speed.
Answer:
v = 2.85 m/s
Explanation:
Given that,
A skipper on a boat notices wave crests passing his anchor chain every 5.6 s.
The distance between wave crests to be 16 m.
We need to find the speed of the waves. The speed of a wave can be calculated by the formula as follows :
[tex]v=f\lambda\\\\v=\dfrac{\lambda}{T}\\\\v=\dfrac{16}{5.6}\\\\v=2.85\ m/s[/tex]
So, the speed of the wave is 2.85 m/s.
a load of 800 newton is lifted by an effort of 200 Newton. if the load is placed at a distance of 10 cm from the fulcrum. what will be the effort distance ?
Answer:
40 cm
Explanation:
We are given that
Load=800 N
Effort=200 N
Load distance=10 cm
We have to find the effort distance.
We know that
[tex]load\times load\;distance=Effort\times effort\;distance[/tex]
Using the formula
[tex]800\times 10=200\times effort\;distance[/tex]
Effort distance=[tex]\frac{800\times 10}{200}[/tex]
Effort distance=[tex]\frac{8000}{200}[/tex]
Effort distance=40 cm
Hence, the effort distance will be 40 cm.
Which of the elements below have seven electrons in their outermost energy levels? A.) Cr, Mn, and Fe B.) Br, I, and Ci C.) O, S, and Se D.) He, Ne, and Ar
Answer:
B
Explanation:
the Halogen families have 7 valence electrons
the unit of force and pressure are called derived unit
Answer:
yes
Explanation:
because they can be derived in the form of base units
Lifestyle practice that can improve your quality of life
Explanation:
And keep changing gradually.
Eat a variety of foods. ...
Base your diet on plenty of foods rich in carbohydrates. ...
Replace saturated with unsaturated fat. ...
Enjoy plenty of fruits and vegetables. ...
Reduce salt and sugar intake. ...
Eat regularly, control the portion size. ...
Drink plenty of fluids. ...
Maintain a healthy body weight
can anyone please help me
Answer:its most likely c
Explanation:
