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Drag- Pull something or someone

the force excreted by fluids (air. water) is called drag

tq

Friction is not caused mainly by surface roughness. According to the book "Sliding Friction" by Bo N. J. Persson, friction is caused by weak electromagnetic forces between molecules, such as experienced in hydrogen bonds and Van der Waal bonds. If two electrically neutral, non-polar atoms are brought close enough together, they induce electric dipole moments in each other which then attract. These weak bonds cause the two objects with surfaces touching to be attracted, making it hard to slide one object along the other. Additionally, the sliding motion can generate vibrations (phonons) in the objects touching, which takes energy away from the sliding motion and therefore slows down the objects. Because friction is mainly caused by electrical attraction and not surface roughness, smooth objects can still have relatively high friction coefficients. In fact, nanoscopically smooth objects experience very high friction (as long as their chemical structure promotes significant electromagnetic forces) because they have much more of their surface in contact. Surface roughness can become significant if the roughness is very high. The best way to lower the friction of a surface is to combat both. Smooth down the surface to lower surface roughness, and then sprinkle on a lubricant which gets in the way of the chemical bonding, such as oil or graphite.

let the other string eqn. be,y = asin(wt + kx)put x=0 in first wave eqn.we get,y = asin(wt)equate both,asin(wt + kx) – asinwt =0a(sin(wt +kx) – sinwt) = 0a cannot be zero.

WE will get -a sin (wt+kx)

-a Sin(wt+kt) is the right answer

Given, Force, F= 4kg-wt=4*9.8= 39.2Nacceleration, a=4m/s^2so, mass, m=F/a=39.2/4=9.8 kg

(c)100 times in 100S= 1.0 S

1.0 sec because 100 times means 100 sec

According to Kepler law

32*7/36= 8*7/9= 56/9thanks

-32 × (-7/36) = 224/36 =56/9

Static friction is the friction between two surfaces that are not in relative motion with each other, while Dynamic (aka Kinetic) friction is the friction between two surfaces that are in relative motion with respect to each other.

Static friction is the opposing force which comes into play when two bodies or one body and surface in contact tend to move but the actual motion has not yet started.

Sliding friction is a type of kinetic friction which operates when a body is actually sliding over another surface.

The maximum limit of static friction is called limiting friction . So,the coefficient of static friction is usually more than that of sliding or kinetic friction.

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The answer is Option 2.

logx=3/4log(4/3)logx=3/4(log4-log3)logx=3/4(0.12)logx=0.094X=e^0.094X=1.0985

dx indicates The smallest change in the position of a Particle

option 3- f1=f2=0

In a brushlessexciter, excitation power is generated by a small alternator whose armature is driven by the maingeneratorshaft. The armature output leads are connected to a rectifier, which is also shaft mounted and rotating. The DC output of rectifier is fed to the rotating field winding of the maingenerator.shut generator.

please explain briefly

ans me plzz

Shuntconnection is connection of a component/device in circuit which lets the current to pass through another path in between the points where it is connected. The usage is the same as describing ashuntacross a galvenometer to make an ammeter. The low value resistance is “inshunt” with the moving coil meter.

Given:Ig=1%IGalvanometer resistance=GShunt resistance=?Formula:S=G.Ig/(I-Ig)Solution:S=G(1%I)/(1-1%I)=G(1%/99%)=G/99 ohmsS=G/99 ohms

are equal to each other

When a real gas is compressed, its molecules come closer. Their mutual interactions become stronger. This increases the magnitude of potential energy. But potential energy is negative. Hence the total energy of the compressed gas decreases. However, the kinetic energy is same for both the compressed and rarefied gases as both are at the same temperatures.

10¹² h is the answer

In general, if we compress a gas, the temperature of that gas will increase. The compression increases the pressure of the gas. There is a bit more, depending on how an investigator choses to look at the problem. If the pressure remains constant and the volume goes down, the temperature goes down.

what happens to its internal energy

It should be option A as the displacement attains a maximum value and then decreases so the velocity must have changed it is direction i.e. have become negative.

Area under force time graph is equal to change in momentum

But what if the graph first goes up and then goes down the time axis?

I don't know the answer please like my also

The satellite at smaller height has more speed because orbital velocity is inversely proportional to the square root of r.Escape velocity = √(2GM/R)

it's wrong

the slope of momentum vs time graphgive the (Force) because f=dp/dt

Force us the quantity given by the slope of momentum vs time graph

In classical mechanics,impulse(symbolized by J or Imp) is the integral of aforce, F, over the time interval, t, for which it acts. Sinceforceis a vector quantity,impulseis also a vector in the same direction. ... A resultantforcecauses acceleration and a change in the velocity of the body for as long as it acts.

SI unit:

Newton second (N⋅s)

Other units:

pound⋅s

Common symbols:

J, Imp

alpha = firing angleVm = max value

Distance between the two balls after 6 secs = ½ * 10 * 62= 180

Relative velocity of second ball(wrt first ball) so that it can cover this distance = 180/ 12 = 15m/s

Velocity of first ball (at t= 6) = 10* 6 = 60

v= 60 + 15 =75m/s

iron