physics class 9 chapter 8 please tell​ please

Answer:

mechanical waves,

.

the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone.

.

If the amplitude increases the volume increases and vice versa.

.

The type of medium affects a sound wave as sound travels with the help of the vibration in particles.

.

The higher the frequency, the shorter the wavelength.

Explanation:

Answer:

1 . Soundwave

2. pitch are sounds that are high or low corresponding and according to a certain frequency measured in Hertz

3. volume is the increase in sound or decrease in sound how loud or soft something is while amplitude is strength of sound

4. frequency is measured in Hertz one wave per second and wavelength is distance between corresponding points of two recurring and consecutive sound waves

Answer:

The experimental scientist

Explanation:

Hydraulic Pressure-Control, On-Off Deluge Valve

FP-400Y-5DC

The BERMAD model 400Y-5DC is an elastomeric, hydraulic line pressure operated deluge valve, designed specifically for advanced fire protection systems and the latest industry standards. The 400Y-5DC is activated by a hydraulically operated relay valve, through which opening and closing of the valve can be controlled either with a remote hydraulic command or with a wet pilot line with closed fusible plugs. An integral pressure reducing pilot valve ensures a precise, stable, pre-set downstream water pressure. The optional valve position indicator can include a limit switch suitable for Fire & Gas monitoring systems. The 400Y-5DC is ideal for systems that combine a remote wet pilot line with a high pressure water supply.

Answer:

C) Potential energy due to intermolecular forces.

Answer:

0.2

Explanation:

The given parameters are;

The acceleration of the train, a = 0.2·g

The mass of the person standing on the train = m

Let μ represent the coefficient of static friction, we have;

The force acting on the person, F = m × a = m × 0.2·g

The force of friction acting between the feet and the floor, [tex]F_f[/tex] = m·g·μ

For the person not to slide we have;

The force acting on the person = The force of friction acting between the feet and the floor

F = [tex]F_f[/tex]

∴ m × 0.2·g = m·g·μ

From which we get;

0.2 = μ

The coefficient of static friction that must exist between the feet and the floor if the person is not to slide, μ = 0.2.

Answer:

-29.9907

Explanation:

c = Q / (mΔT)

You're looking for ΔT, so you would plug in what you already know and get C= -12540/(100 x ΔT)

then you would solve

Answer:

Our weight on moon is less than it would be on Earth.

Explanation:

Due to a difference of the strength of gravity on the moon. The moon's gravitation force is determined by the mass and the size of the moon. Since the moon has significantly less mass than the Earth, it will not pull objects toward itself at the strength that Earth will. This means that if you went to the moon you would weigh less, even though your mass stays the same.

Answer:

the change in the internal energy of the balloon is 3,300 J

Explanation:

Given;

heat gained by the balloon system, Q = 6,400 J

work done on the surrounding air by the balloon, W = 3,100 J

The change in the internal energy of the system is calculated from the first law of thermodynamics;

ΔU = Q - W

where;

ΔU is the change in the internal energy of the balloon;

ΔU = 6,400 J - 3,100 J

ΔU = 3,300 J

Therefore, the change in the internal energy of the balloon is 3,300 J

Answer:

[tex]t = \frac{\pi}{8}, \frac{\pi}{4}, \frac{3\pi}{8}, \frac{3 \pi}{4}[/tex]

Explanation:

The equation of force is

F = 4 sin 4 t

Compare with the standard equation

f = A sin wt

where, w is the angular frequency and A is the amplitude.

Now

w = 4 rad/s

Let the time period is T.

the relation for the time period is

[tex]T = \frac{2\pi}{w}\\\\T = \frac{2 \pi}{4}\\\\T = \frac{\pi}{2}[/tex]

the time period is defined as the time taken by the body to complete one oscillation.

So, the velocity is zero at the extreme points where the object is at time, T/4 and its odd T/2, 3T/4, 3T/2, etc.

So, the velocity is zero at time

[tex]t = \frac{\pi}{8}, \frac{\pi}{4}, \frac{3\pi}{8}, \frac{3 \pi}{4}[/tex]

hope it is helpful to you

Answer:

I = 0.2 A

Explanation:

Lamp is rated at 300 mA

I_lamp = 300 mA = 0.3 A

Voltage is; V = 3V

Thus; Resistance is given by;

R = V/I

R = 3/0.3

R = 10 ohms

Now, since the ammeter of 5 ohms is connected in series with the lamp. Thus equivalent resistance;

R_eq = 10 + 5

R_eq = 15 ohms

Ammeter current will be;

I = V/R_eq

I = 3/15

I = 0.2 A

Every living things gives off thermal energy in the form electromagnetic waves. The electromagnetic wave releasing off is  infrared radiation. Hence, option C is correct.  .

Electromagnetic waves are associated with a combined electric field and magnetic field. They can pass through vacuum as well as through a medium. Unlike mechanical waves, all the electromagnetic waves are transverse waves.

The oscillation of particles is in the direction perpendicular to the wave propagation. There are 7 types of  radiations in the electromagnetic spectrum. The light we see is called visible light.

The infrared waves are located in between microwaves and visible light. Every  living thing gives off thermal energy in the form of infrared radiation. Hence, option C is correct.

Find more on infrared waves:

https://brainly.com/question/30309627

#SPJ2

Answer:

I = sum m *r^2    where m represents the (small) individual masses and r is the distance of that mass from center of rotation

Note:  sum m = M

For the hoop given all masses are at a distance RRR from the center of rotation

I = MMM * RRR^2

Answer:

Its all about figuring out what numbers you times by

Explanation:

soooooooooo just x the numbers until you get it right, and i'm guessing your in a school soooo ask your teacher aswell :)

Answer:

More than two million electron volts.

Explanation:

More than two million electron volts energy are needed to break or split a deuteron into a proton and a neutron. Nuclear binding energy is the type of energy that is required to split an atom's nucleus into protons and neutrons. The deuteron is an isotope of hydrogen that is composed of a proton and a neutron and it is a stable particle. Very huge amount of energy is needed for the splitting of nucleus due to the presence of heavy particles i.e. proton and neutron.

Answer:

Negative ion

.................

Answer:

shushhhgggvvv vgfxgh

Explanation:

gey laahhg

Answer:

Explanation:

You need something that relates distance to what the gravitational pull is. You can set up a complex sort of proportion. What you need is a number that is comparable to 9.81 or you can just use the Gravitational Force formula with a 4 tier fraction.

Givens

x = the additional distance toward outer space above the radius of the earth.

G is the gravitational constant.

m1 = the person's mass (which does not change no matter where you are).

m2 = the earth's mass

F1 = 588 N

F2 = 300 N

Formula

[tex]\frac{F1}{F2} = \frac{588 N}{300N}=\frac{\frac{Gm1*m2/}{6400^2} }{\frac{G*m1*m2}{(6400 + x)^2} }[/tex]

Solution

G*m1*m2 all cancel. So what you get looks like this.

[tex]\frac{588}{300} = \frac{(6400 + x)^2}{6400^2}[/tex]

Cross Multiply

588 * 6400^2 = 300*(6400+x)^2  Now all you need do is solve for x.

x will be in km.

588*40960000 = 300 * (40960000 + 12800x + x^2)

1.2288*10^10 + 3840000x + 300x^2  = 2.408448*10^10

300x^2 + 3840000x + 1.2288*10^10 = 2.408448 * 10^10  

Subtract 2.409448 * 10^10 from both sides.

300x^2 + 3840000x - 1,179648 * 10^10

Now use the quadratic formula

I'm guessing I should have converted this to meters because I'm getting ridiculous numbers. They are already large enough as you can see. The method is correct, even if the numbers are not.  

Answer:

Air.

Explanation:

To know which option is correct, let us consider the relationship between velocity and the wavelength of a wave. This is illustrated below:

Velocity, wavelength and frequency are related by the following equation:

Velocity = wavelength × frequency

v = λf

From the equation above, we can see clearly that the velocity is directly proportional to the wavelength.

This means that an increase in the wavelength will lead to an increase in the velocity and also, a decrease in the wavelength will lead to a decrease in the velocity.

Now, considering the table given in the question above, we can see that the wave has a higher speed in air. This simply means that the wave will also have a higher wavelength in air.

Thus, the correct answer to the question is: air

Answer:

Deflating the tires by pulling the valve stems

Explanation:

When an accident happens, the EMT process is to take off the top of the vehicle of the highly damaged vehicle so that it can easily be assessed to rescue the vehicle occupants. This creates a bigger exit for the rescuers to take out the people. Vehicle extrication means removing the vehicle from around someone involved in a fatal collision, when other other ways of exiting is not advised or possible. to stabilize the vehicle you have to deflate all tires by pulling the valve stems.

Such asSuch ToSuch aSuch as طHow do I send the answer to the question?OkI don't know how to use this program

Answer:

MOMENTUM = 40kg ms-¹

hope it helps

have a nice day

Answer:

2.9

Explanation:

es 2 minutos con 9 segundos seria algo así (1450)÷(500)

Answer:

b. 12.5 mAs, 70 kVp

Explanation:

The given parameter are;

The initial exposure factors := 10 mAs and 70 kVp

The initial Grid Ratio, G.R.₁ = 8:1

The Grid Ratio with which the radiographer desires to increase the scatter absorption, G.R.₂  = 12:1

Given that the lead content in the 12:1 grid, is higher than the lead content in 8:1 grid and that 12:1 grid needs more mAs to compensate, and provides a higher image contrast, the amount of extra mAs is given by the Grid Conversion Factors, GCF, as follows;

The GCF for G.R. 8:1 = 4

The GCF for G.R. 12:1 = 5

Therefore, given that the mAs used by the radiographer for 8:1 Grid Ratio is 10 mAs, the mAs required for a G.R. of 12:1 in order to maintain the same exposure is given as follows;

mAs for G.R. of 12:1 = 10 mAs × 5/4 = 12.5 mAs

Therefore the new exposure factors are;

12.5 mAs, 70 kVp

Answer:

Explanation:

First I converted the km/h to m/s, which is the more common unit for velocity. In m/s, 105 km/h is 29.2. Thus, to find the x component of the vector:

29.2cos25 = 26 m/s

If you want it in km/h:

105cos25 = 95 km/h

Answer:

6Eo

Explanation:

Answer: The uses of static electricity include:

--> photocopying machines

--> precipitators

The dangers of static electricity include:

--> sparks that can lead to explosion

--> Damage to electronic equipment

Explanation:

STATIC electricity is defined as the imbalance that exists between a positive and a negative charge either within or outside an object. This is because all physical objects are made up of atoms which contains protons, electrons and neutrons. The protons are positively charged, the electrons are negatively charged, and the neutrons are neutral. This shows that physical objects are made up of charges.

Opposite charges attract each other (negative to positive). Like charges repel each other (positive to positive or negative to negative). Most of the time positive and negative charges are BALANCED in an object, which makes that object neutral.

Applications( uses) of static electricity include:

--> photocopying machines: Inkjet photocopiers and printers use static electricity to guide a minute jet of ink to the page’s precise position.

--> precipitators: the static electricity is applied in an electrostatic precipitator whereby they remove smoke from waste gases before they pass out of the chimneys in power stations that burn fossil fuels.

The disadvantages (dangers) of static electricity include:

--> Sparks that can lead to explosion: sparks generated from static electricity can cause fires or explosions due to the ignition of flammable or explosive mixtures.

--> Damage to electronic equipment: this is due to components from electrostatic discharge.

Answer:

Heat required = mass× latent heat Q = 0.15 × 871 ×

The heat required to evaporate 0.15 kg of lead at 1750°C will be 130,650 J.

The movement of energy from a hot to a cold item is characterized as heat. Heat energy flows from a hot material to a cold one.

This occurs because faster-vibrating molecules transmit their energy to slower-vibrating ones.

The given data in the problem is;

m is the mass of lead =  0.15 kg  

T is the temperature = 1750°C,

The latent heat of vaporization for lead is, [tex]\rm L_V[/tex] = 871 × 10³ J/kg.

The heat is found as;

[tex]\rm Q= m \times L_V \\\\ \rm Q= 0.15 \times 871 \times 10^3 \\\\ Q=130,650 \ J[/tex]

Hence the heat required to evaporate 0.15 kg of lead at 1750°C will be 130,650 J.

To learn more about the heat refer to the link;

brainly.com/question/1429452

Answer:

Look at work

Explanation:

Your given the mass of planet M and radius as well as second mass.

Use universal gravitation law to find force of gravity

Fg= Gm1m2/r^2

Plug in givens

Fg= 553.6 N

Use newtons second law

Fg= ma

553.6N=5a

solve for a= 110.72m/s

Weight is 553.6N