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Cotton wool remains fluffy because of air trapped in it. When a lump of cotton wool is dipped in water, the air goes out of the lump. Due to this, the cotton wool shrinks when dipped in water.

Cotton woolremains fluffy because of air trapped in it. When alump of cotton wool isdipped inwater, the air goes out of thelump. Due to this, thecotton wool shrinkswhen dipped inwater.

the spogy tissue called velamen is present in epiphytic roots.

Energy Lost by the hot water=Energy Gain by the cold waterLet temperature of mixture be x540(80-x) = 540(x-0)2x = 80Temperature of mixture is 40

volume of cube = (length)³ = (1.2×10-²)³ = 1.728×10^-6 m³

option C

The roof of the movie theater as well as the conference hall are intentionally made curved . This is done so that the sound produced can be reflect from the roof parts and also from the walls so that the sound produced can be reached in all part of the theater or the conference hall. This helps the sound to reach to the every person in the hall. This is purely made on the principle of reflection of the sound. These curves can result in the process of reverberation .

Anything inside trigonometric identities have no dimension (radian and degree are dimensionless ) . So ‘wt’ should have no dimension , since dimension of ‘t' is sec, thus dimension of w is sec^-1 or 1/sec.

Or simple w= 2*pi/time

2*pi is dimensionless, this dimension of w is 1/secso option c is the correct answer

In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. The principle is named after Daniel Bernoulli who published it in his book Hydrodynamica in 1738.

we will use angular momentum conservation in this question. w = angular velocity.

initial angular momentum is Iw = (Mr²/2)*wfinal angular momentum = I'w' I' = Mr²/2 + 2*(m)*(r²/4) = Mr²/2 + mr²/2 I'= r²/2*(M+m)

now Iw = I'w' => w' = Iw/I' = {(Mr²/2)*w}/r²/2*(M+m) = Mw/(M+m).

F= Gm1m2/r² is the required formula

Newton's Law of Coolingstates that the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature (i.e. the temperature of its surroundings).

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Ans :- Ohm's law states that at a constant temperature, current 'I' through a conductor between two points is directly proportional to the potential difference or voltage 'V', across the two points. That is, This constant is called as the resistance (R) of the conductor.

Ohm'slaw show the relationship between potential difference and current, where as it states that potential difference is directly propotional to currentmathematical expression for ohm's law is VαI i.e., V=IR

Objective :-To prove the law of reflection through a plane mirror.

Things required:-Soft board,white sheet of paper , optical pins , mirror , pencil, protactor and ruler .

Method :-

1-Place the paper on the board and fix

2-Place the mirror vertically on the white sheet of paper and trace its edge.

3-Draw a line at right angles to the edge of the edge of the mirror to act as the normal-ON.

4- Stating with angle i as 30 degree , draw an incident ray and place two pins, P and Q along it as shown5-With your eyes at position shown, place two other pins R and S to coincide with the images of P and Q as seen in the mirror

6-Remove pins R and S and join the dots left with a straight line

7-Measure and record angle r.

8-Repeat procedure 4,5,6 and 7for angles i = 35 degree, 40 degree, 45 degree, 50 degree and 55 degree.

Record the results in a table.

On carefully observing the result on will clearly see that :-

1-The angle of incidence equals the angle of reflection.

2-Incident ray, Reflected ray and the normal at the point of incidence lie in the same plane.

Hence the laws of reflection proved.

Weeds are unwanted plants. They grow with crops and compete for nutrients and water with the main crop. So weeds are very harmful.

(i) The manual removal includes physical removal of weeds by uprooting or cutting them close to the ground, from time to time.

(iI) Tilling before sowing of crops helps in uprooting and killing of weeds, which may then dry up and get mixed with the soil.

(iiI) Weeds can also be controlled by using certain chemicals, called weedicides like 2, 4-D.

because the pupil is actually the hole, from where the light enters to form image..

so , there is no light that gets reflected from there. and in turn, it appears to to black.

weeds are wanted plants which grown a long with the crop. weeding is down either manually by uprooting the weeds with hands or by using tools such as horrow and trowel. the two common weeds are CHENOPODIUM and AMARANTHUS , and two Weedicides are METACHLOR and DALAPON.

weed is planted in the ground when it turns out to be done they crop it and turn it into grass

the most common weeds is the grass

option 2)Angle of contact will remain same. It is independent of inclination.

Pencil appears bent because of a light phenomenon called refraction.As light travels through water with a slower speed,it changes its path to compensate for the change in medium.

If the body is in constant velocity, then net force acring on it is zero. Gravity and frictional force are the only forces that are acting here, neglecting air resistance.

Hence, frictional force is equal to Gravitational force.Ff=mgsin30∘=mg/2=5×10/2=25N

not in theory do it numerically

As we know, Gravitational potential energy = - GM /r

and orbital velocity, v0= vGM/R+h

Ef= ½ mv^20– GMm/3R = ½ m GM/3R – GMm/3R

= GMm/3R (1/2-1) = - GMm/6R

Ei= - GM/R + K

Ei= Ef

Therefore minimum required energy, K = 5GMm/6R

why we calculated the kinetic energy

Due tobufferspring, the time of impactbetween the bogiesincreases, and the force actingbetween the bogies(F = Impulse / time) decreases. Consequently, passengers sitting inside thebogiesdo not experience strong jerks. For the same reason shockers areprovidedin all vehicles.

Electrical power is the rate at which electrical energy is converted to another form, such as motion, heat, or an electromagnetic field. The common symbol for power is the uppercase letter P.

When expressed in watts, power is sometimes called wattage.

the ability to control people or things or to do something is called power.

(in hindi also

लोगों या वस्‍तुओं को नियंत्रित करने या कोई काम करने की योग्‍यता; सामर्थ्य, क्षमता)

power is the rate of doing work or of transferring

We know that Horizontal range R = u^2sin 2theta/g --------------- (1)

We know that Maximum height H = u^2sin^2 theta/2g ------------- (2)

On solving (1) and(2) we get

R/H = 4/tan theta --------------------- (3)

Given, R = 50m, Height = 10, substitute in (3), we get

50/10 = 4/tan theta

tan theta =4/5

theta = 38.6598 degrees.

Hope this helps!

psuedo force will act on opposite direction of the movement.

here.. tan∅ = a/g so, a = gtan∅

ye to bhut bada hai samajh nhi aa raha

As we can see two forces are being applied on the blockbut 4N force will be the resulting one as it's greater than 3Nit will be a sort of pulling force

The answer for the given question is 0.5 N

option 4 is correct answer

0.5N it is correct answer

Option 4)is correct answer

0.5 N is the write answer

0.5 N is the correct answer

displacement in v-t graph can be found by calculating the are of enclosed figure..dis in first 3 sec=area of triangle =1/2*3*2=3mdis in next 1 sec=1/2*1*2=-1m(due to negetive velocity)dis in next 1 sec=area of rect.,=1*2=2net displacement=3-1+2=4m

Hooke’s law states that within the elastic limit, stress developed is directly proportional to the strain produced in a body.

tnx

Electricity flows at two different voltages. If a bird perches on two wires, of if its body touches an electric pole while perched on the wire, then it makes a path for electricity to flow between two different voltages.wire. But when birds sit on wires, there are always on the same as electric potential, so they won't get shocked.

thank u bro