28. Sound can be heard around a corner because of

Answer:

W = 12.568rads

V = 1.8852m/s

Explanation:

Data:

r = 15cm = 0.15m

t = 10s

Revolutions = 20

Frequency (F) = number revolutions/ time take complete it

F = 20 / 10 = 2Hz

Angular velocity (w) = 2 * 3.142 * F

Note: 3.142 = value of pi

W = 2*3.142*2 = 12.568 rads

Linear velocity (v) = w*r

V = 12.568*0.15 = 1.8852m/s

Answer:

0.050 m

Explanation:

The strength of the magnetic field produced by a current-carrying wire is given by

[tex]B=\frac{\mu_0 I}{2\pi r}[/tex]

where

[tex]\mu_0=4\pi \cdot 10^{-7} H/m[/tex] is the vacuum permeability

I is the current in the wire

r is the distance from the wire

And the magnetic field around the wire forms concentric circles, and it is tangential to the circles.

In this problem, we have:

[tex]I=1.41 A[/tex] (current in the wire)

[tex]B=5.61\mu T=5.61\cdot 10^{-6} T[/tex] (strength of magnetic field)

Solving  for r, we find the distance  from the wire:

[tex]r=\frac{\mu_0 I}{2\pi B}=\frac{(4\pi \cdot 10^{-7})(1.41)}{2\pi (5.61\cdot 10^{-6})}=0.050 m[/tex]

f = 1/3 swings per second

or

f = 1 swing per 3 seconds

The frequency of a swing with a period of 3 seconds is approximately 0.33 Hz, calculated using the relationship f = 1/T.

The question is asking us to calculate the frequency of a swing given its period. The known period of the swing is 3 seconds. To find the frequency, which is the number of cycles the swing completes in one second, we can use the relationship between period (T) and frequency (f), which is f = 1/T. Thus, for a period of 3 seconds, the frequency is simply f = 1/3 seconds = 0.333... cycles per second, or approximately 0.33 Hz when rounded to two decimal places.

Answer:

2000000j

Explanation:

m*g*h

2000*100*10

=2000000

Answer:

B

Explanation:

When one bulb burns out, all the other lights stay lit.In a parallel circuit, each component is connected to the power source directly.

1 lb = 4.45 Newtons (rounded)

199 lbs = approx 885 Newtons

Final answer:

The box sliding down the hill with an initial velocity of 3 m/s and accelerating at 2 m/s² will be going 11 m/s after 4 seconds.

Explanation:

The question involves a box sliding down a hill with an initial velocity of 3 m/s, which then accelerates at 2 m/s². To find out how fast the box will be going after 4 seconds, we apply the kinematic equation:

v = u + at,

where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Plugging in the values, we get:

v = 3 m/s + (2 m/s² * 4 s) = 3 m/s + 8 m/s = 11 m/s.

The box will be going 11 m/s after 4 seconds.

Answer:

In the process some of the mass of the hydrogen is converted into energy. ... The sun and stars do this by gravity.

Explanation:

Answer:

#See solution for details.

Explanation:

-Friction is the force exerted on an object moving against it.

-Friction acts in the opposite direction to the object's motion.

-As such, friction reduces the motion of an object. The object is usually slowed down. The resultant motion of the object is less than the force applied on it.

The option stating that the observer must be placed within the focal length is false or not a necessary condition for magnification.

Explanation:

Lens are used for magnification provided the nature of the lens is known and by positioning the object at correct position. So the object should be placed in the focal point of the lens for perfect magnification, it can also be kept within the focal point or focal length. But the object should not be kept beyond the focal length of the lens.

So among the given options, the object and image should be on the same side of the lens for magnification is true. Then the nature of lens should be converging for magnification is also true. And the most important point that the object should be placed within the focal length of the lens is the most mandatory for obtaining magnification. So the option stating that the observer must be placed within the focal length is false or not a necessary condition for magnification.

Answer:

TRUE

Explanation:

The gravitational force between two objects becomes weaker if the two objects are moved apart and stronger if they are brought closer together; that is, the force depends on the distance between the objects

Answer:

Air resistance: 68.6 N

Explanation:

For the skydiver falling down, there are two forces acting on him:

- The force of gravity, of magnitude

[tex]W=mg[/tex]

where

m = 7.0 kg is the mass of the skydiver

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

This force acts in the downward direction

- The air resistance, R, in the upward direction

So the net force on the skydiver is:

[tex]\sum F=mg-R[/tex]

According to Newton's second law of motion, the net force is also equal to mass times acceleration:

[tex]\sum F=ma[/tex]

However, in this problem the skydiver is falling at constant velocity, so his acceleration is zero:

[tex]a=0[/tex]

Therefore, the net force is zero:

[tex]\sum F=0[/tex]

And so we can find the magnitude of the air resistance, which is equal to the weigth of the skydiver:

[tex]mg-R=0\\R=mg=(7.0)(9.8)=68.6 N[/tex]

This question involves the physics concept of terminal velocity. It's the constant speed a skydiver descends when the force of gravity equals the upward force of air resistance.

The subject of this question involves a concept in physics known as terminal velocity. When a skydiver jumps out of a plane, gravity pulls them downwards, while air resistance pushes upwards. As the skydiver falls faster, air resistance increases until it is equal to the pull of gravity. At this point, the skydiver no longer accelerates and falls at a constant velocity. This is the terminal velocity. In this particular case, the fact that the 7.0kg skydiver is descending at a constant velocity tells us that he has reached his terminal velocity.

https://brainly.com/question/31760874

#SPJ6

The weight of the needle = 0.007 N

Explanation:

Step 1 :

Given,

Length of the needle = 5 cm = 5 × [tex]10^{(-2)}[/tex] m

Surface tension of the water =0.07 N/m​

We need to find the weight of the needle.

Step 2 :

We have

weight = (surface tension) × 2l

where l is the length of the object

The total contact length between the needle and water is 2 times the length of the needle.

Therefore

weight of the needle = 0.07 × 2 × 5 × [tex]10^{(-2)}[/tex]  = 0.007 N

Step 3 :

Answer :

The weight of the needle = 0.007 N        

The weight of the needle is 0.0035N

In order for a needle to rest on the surface of water without wetting, the force due to the weight of the needle must be balanced by the surface tension of the water. The weight of the needle can be calculated using the formula:

Weight = Mass x Acceleration due to gravity

Given that the length of the needle is 5cm and the surface tension of the water is 0.07N/m, we can find the weight of the needle by converting the length into meters and multiplying by the surface tension.

Weight of the needle = Length x Surface tension = 0.05m x 0.07N/m = 0.0035N.

Learn more about water's surface here:

https://brainly.com/question/36734582

#SPJ3

Explanation:

The work done to lift the bag of weight mg through height 2.5 m is 400 J

The work done can be found by relation  W = mg x h

Thus mg = [tex]\frac{W}{h}[/tex] = [tex]\frac{400}{2.5}[/tex] =  160 N

Therefore the man have to apply the force of 160 N

Answer:160newtons

Explanation:

Work=400J

Distance=2.5m

Time=2 seconds

Force=?

Force=work/distance

Force=400/2.5

Force=160

Force=160 newtons

USE MORE COILS OF WIRE AROUND THE NAIL

Explanation:

To increase the strength of an electromagnet, the following strategy is adopted in order to have better efficiency.

The best method which suits for increasing the strength of electromagnet is to increase the number of turns around the nail.

If we increase the number of turns up to a specific value the magnetizing property of magnet is enhanced. So that to increase the strength , add more number of turns to the existing turns of coil.

Answer:

Amplitude: B

Crest: A

Trough: C:

Wavelength: D

Explanation:

The amplitude of the wave is defined as the distance from the equilibrium position of the wave to its crest or troughs; therefore,

Amplitude: B

The Crest of a wave is its highest point from its equilibrium position; therefore,

Crest: A

The trough of a wave is its lowest point measured from equilibrium position; therefore,

Trough: C

The wavelength of a wave is the distance between two identical points on a wave; therefore,

Wavelength: D.

The parts of a transverse wave are the amplitude, crest, trough, and wavelength.

Amplitude: The amplitude of a transverse wave is the maximum displacement of a point on the wave from its equilibrium position. It represents the intensity or strength of the wave. For example, in a water wave, the amplitude would be the height of the wave from the water's surface.

Crest: The crest of a transverse wave is the highest point of the wave above the equilibrium position. It is the point where the displacement is maximum in the upward direction.

Trough: The trough of a transverse wave is the lowest point of the wave below the equilibrium position. It is the point where the displacement is maximum in the downward direction.

Wavelength: The wavelength of a transverse wave is the distance between two consecutive crests or troughs of the wave. It is usually represented by the symbol λ (lambda) and is measured in meters. It determines the spatial extent of the wave.

https://brainly.com/question/23165088

#SPJ12

Answer:

Electric energy moves through the wire to the lamp's bulb. In the bulb's filament, electric energy transforms into thermal energy and light energy.

Explanation:

There are three plate boundaries: Constructive, Destructive and transform plate boundary. At constructive plate boundary mountains form, at destructive plate boundaries earthquake and volcanism occurs and at transform boundary faults occur.

Explanation:

Plates are solid and rigid mass. It mainly floats over asthenosphere which is a part of upper mantle. There are seven major plates and twenty minor plates. The zone between two plates are known as plate boundary and the edge of a plate is known as plate margin.

There are three plate boundaries: Conservative, destructive and transform plate boundary. Where two plates collide with each other known as destructive plate boundary and where two plates move in opposite direction from each other known as constructive plate boundary. Where two plates slide each other called transform fault.

Answer:

Volcanoes are one kind of feature that forms along convergent plate boundaries, where two tectonic plates collide and one moves beneath the other.

Explanation:

Answer: A b e

Explanation:

Systems are a computer, a car, and a coffeemaker. Therefore, options A, B, and D are correct.

A system refers to a well-defined portion of the physical universe that is the subject of study or analysis. It is a fundamental concept used to simplify and focus investigations into the behavior and interactions of objects or components within a specific region of interest.

A physics system can consist of one or more physical objects, particles, or components that are the primary subjects of study. These components are chosen based on the specific physics principles or phenomena being investigated. Therefore, options A, B, and D are correct.

Learn more about systems, here:

https://brainly.com/question/3602141

#SPJ3

The force on the book that has a mass of 50 grams and an acceleration of 5 m/s² is 250N.

The force of an object can be calculated by multiplying the mass by its acceleration as follows:

Force = mass × acceleration

According to this question, a book has a mass of 50 grams and an acceleration of 5 m/s². The force is as follows:

Force = 50 × 5

Force = 250N

Therefore, the force on the book that has a mass of 50 grams and an acceleration of 5 m/s² is 250N.

Learn more about force at: https://brainly.com/question/13191643

The correct force on the book is 2.5 N.

To find the force on the book, we can use Newton's second law of motion, which states that force is equal to mass times acceleration (F = m × a).

Given:

- The mass of the book (m) is 50 grams. To convert grams to kilograms (since the standard unit of mass in the SI system is kilograms), we divide by 1000. Thus, m = 50 / 1000 kg = 0.05 kg.

- The acceleration (a) of the book is 5 m/s².

Using Newton's second law, we calculate the force (F) as follows:

F = m × a

F = 0.05 kg × 5 m/s²

F = 0.25 kg × m/s²

Since 1 Newton is equal to 1 kgm/s², the force on the book is 0.25 Newtons, or 2.5 N.

Therefore, the correct answer is 2.5 N, which is not listed in the given options. It seems there was a typo in the provided options, as the correct calculation does not result in any of the listed forces. The closest option to the correct answer is 20 N, but it is still incorrect. The correct force is 2.5 N.

Answer: 1.50

Explanation:

Given that:

C (critical angle) = 41.7°

n (index of refraction in benzene) = 2.42

n (index of refraction in benzene) = ?

To get the index of refraction in benzene, Apply the formula n = 1/sineC,

n = 1/sine41.7°

n = 1/sine 41.7°

n = (1/0.6652)

n = 1.50

Thus, the index of refraction for the ray in benzene is 1.50

Answer:

1.61 is the answer

Explanation:

Good luck Acellus users, please rate 5 stars!

Answer:

A) electron

Explanation:

Matter consists of atoms. Each atom consists of three particles:

- The proton: the protons are located inside the nucleus of the atom. They have a mass of [tex]1.67\cdot 10^{-27}kg[/tex], and they have positive electric charge ([tex]+e=+1.6\cdot 10^{-19}C[/tex]). Protons are not fundamental particles, but they actually consists of three quarks (which are instead fundamental particles), in particular of 2 up quarks and 1 down quark.

- The neutron: neutrons are also located inside the nucleus. They have no electric  charge, and their mass is similar to that of the proton (slightly larger). Neutrons consist of three quarks as well, in particular of 2 down quarks and 1 up quark.

- The electron: electrons are located outside the nucleus. They have a mass much smaller than protons (about [tex]9.11\cdot 10^{-31} kg[/tex]) and they have a negative electric charge, opposite to that of the proton ([tex]-e=-1.6\cdot 10^{-19}C[/tex]). The electron is a fundamental particle.

Therefore, the subatomic particle having a negative charge is

A) electron

An electron is the subatomic particle that has a negative charge. Electrons orbit the nucleus, which contains the protons and neutrons, and its negative charge helps to balance the positive charge of the protons.

The subatomic particle that has a negative charge is the electron. Subatomic particles, namely protons, neutrons, and electrons, make up atoms. Protons carry a positive charge and are found in the nucleus of the atom. Neutrons are neutral as they do not carry any charge and are also found in the nucleus. Electrons, which carry a negative charge, move in spaces around the nucleus known as energy levels or electron shells. The negative charge of the electron balances the positive charge of the protons, causing an atom to be neutral under normal conditions.

https://brainly.com/question/34085707

#SPJ3

Answer:

It decreases the frequency by 33.33%

Explanation:

The frequency of a wave is given by the division between its velocity and its wavelength:

f = v/L, where f is the frequency in hertz, v is the velocity in m/s, and L is the wavelength in meter

If we increase the wavelength by 50 percent, we have that L' = 1.5*L (L' is the new wavelength)

Keeping the same velocity, we have the new frequency (f') as:

f' = v/L' = v/1.5*L = (1/1.5)*v/L = 0.6667*f

The new frequency is 66.67% of the old frequency, that is, the old frequency decreased 33.33%.

So, increasing the wavelength by 50% decreases the frequency by 33.33% or 1/3

Increasing the wavelength by 50 percent reduces the frequency of a wave by half.

Increasing the wavelength by 50 percent affects the frequency of a wave on a rope by reducing the frequency by half. The wavelength and frequency of a wave are inversely proportional, meaning that as the wavelength increases, the frequency decreases and vice versa. This relationship is represented by the equation: frequency = speed / wavelength.

For example, let's say the original wavelength of a wave on a rope is 2 meters and the frequency is 10 Hz. If we increase the wavelength by 50 percent, it becomes 3 meters. Using the equation, the new frequency would be: frequency = speed / 3 meters = 10 Hz / 3 = 3.33 Hz.

https://brainly.com/question/32662138

#SPJ3

Explanation:

First thing to understand is how you can manipulate the Ideal Gas Law to your needs. since [tex]\mathrm{PV}=\mathrm{nRT}[/tex] at a constant temperature, [tex]\mathrm{PV} / \mathrm{n}=\mathrm{RT}=[/tex]constant. That means,

[tex]\mathrm{P}_{1} \mathrm{V}_{1} / \mathrm{n} 1=\mathrm{P} 2 \mathrm{V} 2 / \mathrm{n} 21[/tex]

If we say that subscript 1= oxygen and subscript 2= acetylene, then for acetylene,[tex]P 2=(P I V 1 \cap 2) /(\sqrt{2} n 1)[/tex]

Next, we realize from the reaction equation given above that 2 moles of acetylene (n 2 ) react with 5 moles of oxygen (n1). We can plug that right into our equation for P 2, along with the rest of the conditions given in the question:

[tex]P 2=(P 1 V 1 \cap 2) /(V 2 n 1)=\left[(155 a t m)^{*}(5.00 L)^{*}(2 m o l e s)\right] /\left[(25.00 L)^{*}(5 \text { moles }]\right]=124 \text { atm }[/tex]

Answer:

22.13g of C2H2

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

2C2H2 + 5O2 ➔ 4CO2 + 2H2O

Step 2:

Determination of masses of C2H2 and O2 that reacted from the balanced equation. We need to obtain the mass of C2H2 and that of O2 that reacted based on the chemical equation, as it will enhance the process of obtaining the desired result. This is illustrated below:

2C2H2 + 5O2 ➔ 4CO2 + 2H2O

Molar Mass of C2H2 = (12x2) + (2x1) = 24 + 2 = 26g/mol

Mass of C2H2 from the balanced equation = 2 x 26 = 52g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 5 x 32 = 160g

From the balanced equation,

52g of C2H2 reacted with 160g of O2.

Step 3:

Determination of the mass of C2H2 needed to react with 68.1g of O2.

From the balanced equation,

52g of C2H2 reacted with 160g of O2

Therefore, Xg of C2H2 will react with 68.1g of O2 i.e

Xg of C2H2 = (52 x 68.1)/160

Xg of C2H2 = 22.13g

From the calculations made above, 22.13g of C2H2 is needed to react with 68.1 g of O2 to produce 75.0 g of CO2 and 15.35 g of steam

The direction of the velocity vector in circular motion at constant speed is tangent to the circle, while the acceleration vector, known as centripetal acceleration, points toward the center of the circle.

In the specific scenario of a body moving in a circle at a constant speed, the relationship between the direction of the velocity vector and the direction of the acceleration vector is vital to understand. The velocity vector is always tangent to the circle, which means it is drawn along the direction that the body is moving at any point on the circle. The acceleration vector, on the other hand, points toward the center of the circle; this is known as centripetal acceleration. Thus, while the speed remains constant, the direction of the velocity is continuously changing as the body moves along the circular path, resulting in an acceleration towards the center of that path.

λ = 5.7 X 10⁻⁷m

On using quantum dot, it is 351

Explanation:

Given-

Frequency, f = 5.20 x 10^14 Hz

Speed of light, c = 3 X 10⁸ m/s

Wavelength, λ = ?

We know,

λ f = c

λ = c / f

λ = [tex]\frac{3 X 10^8}{5.2 X 10^1^4}[/tex]

λ = 5.7 X 10⁻⁷m

Dot = 2 X 10⁻⁴

So,

2 X 10⁻⁴ / 5.7 X 10⁻⁷m = 351

Answer:

D

Explanation:

The Earth's atmosphere interferes with radio waves less than any other wavelength, so the best kind of telescope to build on the Earth's surface would be a radio telescope. Although visible light telescopes are often built on Earth, they are usually put as high up as possible, such as on mountaintops, where there is less atmosphere to get in their way. Radio telescopes are usually put as far down as possible, such as in valleys, to block out human-generated radio signals coming from other parts of the surface of the Earth.

The telescope that would best be able to pierce through the Earth's atmosphere and function on the surface of the Earth is radio telescope. The correct option is A.

Radio telescopes detect and amplify radio waves from space, converting them into signals that astronomers can use to learn more about the Universe.

Because the Earth's atmosphere interferes with radio waves less than with other wavelengths, a radio telescope would be the best type of telescope to build on the Earth's surface.

Although visible light telescopes are frequently built on Earth, they are typically placed as high up as possible, such as on mountaintops, where there is less atmospheric interference.

Radio telescopes are typically placed as low as possible, such as in valleys, to block out human-generated radio signals from other parts of the Earth's surface.

Thus, the correct option is A.

For more details regarding telescope, visit:

https://brainly.com/question/556195

#SPJ2

Your question seems incomplete, the missing options are:

A. an x-ray telescope

B. an infrared telescope

C. a radio telescope

D. a visible-light telescope

Answer: magnitude

Explanation: I just did it

The Richter scale measures the magnitude of an earthquake. The correct option is A.

The Richter scale is a logarithmic scale for measuring earthquake magnitude, which is a quantitative estimate of the amount of energy generated during an earthquake.

The Richter scale, developed by Charles F. Richter in 1935, provides a numerical value to earthquakes based on the amplitude of seismic waves measured by seismographs.

The Richter scale is logarithmic, which means that each whole number rise reflects a tenfold increase in ground motion amplitude and about 31.6 times greater energy release.

As a result, a higher Richter scale value signifies a more violent and damaging earthquake with greater potential for damage and devastation.

Thus, the correct option is A.

For more details regarding Richter scale, visit:

https://brainly.com/question/14028329

#SPJ2

Your question seems incomplete, the probable complete question is:

The Richter scale measures the __ of an earthquake.

A. Magnitude.

B. Density.

C. Direction.

D. type.