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As temperatures increase, additional heat energy is applied to the constituent parts of a solid, which causes additional molecular motion. Molecules begin to push against one another and the overall volume of a substance increases. At this point, the matter has entered the liquid state

Maximum height = (V sin0)² / 2g= (28 sin30)²/ 2 x 9.8

= 14 x 14 / 2 x 9.8= 10m

time taken to return to the same level=2 v sin0/ g= 2 x 28 x sin30/ 9.8= 2 x 28 x 1/ 2 x 9.8= 2.9 sec

distance from thrower to where the ball returns= v² sin 2Ф/ g= 28 x 28 x sin60/ 9.8= 69.3 m

After 2 seconds velocity is vv = u+atu=0 ,a=-gv = -2g =-20m/s (downward)distance covered in 2 second = Sv2 = u2+2aSu=0 , a=-gS = v2/2a = 400/20 =20it has covered 20 m so remaining distance from ground is 200-20 = 180mnow gravity there is no gravity effect so a=0now we use speed = distance/timet = d/vdistance = 180 ,velocity = 20t = 180/20 = 9secthus body will take further 9 sec to reach the ground

but the answer is 13 seconds

A resistor is an electrical component that has two poles or terminals that enable to be inserted in a circuit to provide some restriction to the electrical current as it flows through. A resistor is also a symmetrical or takes the form of a linear dipole.Symmetricalmeans that its functioning does not depend on the direction in which it is connected, as the polarity can be inverted, producing the same effect in the circuit in which it is inserted.Linearmeans that Ohm's law works for it.These resistors are built by placing an extremely thin layer of graphite on an insulating material and covering them with a coat of insulating paint. The coloured rings are painted on it and a code of colours that correspond to digits from 0 to 9 determine their value.

molecular motion ceases

focal length, f = -15 cm

Distance of image, v = -10 cm

Distance of object, u =?

We know that,

1/v - 1/u = 1/f

1/-10 - 1/u = 1/-15

-1/10 + 1/15 = 1/u

(-3 + 2)/30 = 1/u

-1/30 = 1/u

Therefore u = -30 cm

Thus object is placed 30 cm away from the concave lens. Negative sign shows that object is at 30cm in front of the lens.

The image formed by a plane mirror is always virtual (meaning that the light rays do not actually come from the image), upright, and of the same shape and size as the object it is reflecting. A virtual image is a copy of an object formed at the location from which the light rays appear to come.

1. Image formed by a plane mirror is always virtual and erect.2. The size of the image is equal to that of the object.3. The image formed is as far behind the mirror as the object is in front of it.4. The image is laterally inverted.

Concave mirrorscan produce both real and virtualimages; they can be upright (if virtual) or inverted (if real)

C) is correct

At highest point velocity of particle is vcosθ=200 cos 60=100 m/sLet the mass of particle be 3mIt is given that two particles of equal mass and same magnitude of velocity goes opposite to each other one goes up while other goes down, thus they cancel each other momentum.refer figure below

Now the last fraction of mass will have momentum equal to the momentum of particle before explosion∴ 3m(100)=m(v') according to law of conservation of energy∴ v'=300 m/s along x axis Answer: (b)

Planemirrorsandconvex mirrorsonly produce virtualimages. Only a concavemirroris capable of producing a realimageand this only occurs if the object is located a distance greater than a focal length from themirror'ssurface. 10.The imageof an object is found to be upright and reduced in size.

Convex mirrors produce images that are virtual, erect and diminished .So your answer is (c)

Theimage formedby aplane mirroris always virtual (meaning that the light rays do not actually come from theimage), upright, and of the same shape and size as the object it is reflecting. A virtualimageis a copy of an objectformedat the location from which the light rays appear to come.

option b

When the OBJECT in the apparatus( ..i.e Mirror, Screen, Object) is placed between the focus and the principal axis of the mirror, the mirror reflects the rays in such a way that it diverges, when these diverging rays are traced back to BEHIND the mirror the meet at a point; this is where the image is formed and the IMAGE IS ENLARGED from the ORIGINAL SIZE OF THE OBJECT. THE DIAGRAM is given BELOW

The displacement of the body in first 2 sec = 200cm

Let the initial velocity = u(say) ,

At t = 0, x(0) = 0, v (0) = u (say),

x (t) = 200cm, t = 2s

x(t') = (200 + 220)cm = 420cm

t' = (2 + 5)s = 7s

If a is the uniform acceleration of the particle,

then x(t) = x(0) + v(0)t + ½ at^2

200 = 0 + u*2 + 0.5*a *4

or 100 = u + a ........................................…(1)

Again, x(t') = x(0) + v(0)t' + ½ at^2

420 = 0 + u*7 + 0.5*a*49

60 = u + 3.5a ........................................… (2)

Subtracting (1) from (2),

-40 = 2.5a

or a = -16cm/s2

From equation (1),

u = 100 - (-16) = 116cm/s

Now, t'' = 7s, v(t'') = ?

v(t'') = v(0) + at'' v(t'') = (116 - 16*7) = 4cm/s.

A body travels 2m in first 2s.

Then, 2.2m in next 5s it shows that body is decelerating. So its velocity after 7s could not be 2.22m/s.

it's answer is 200sec

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2.25m/sec2

1)The simplest compound microscope is constructed from two convex lenses . The objective lens is a convex lens of short focal length (i.e., high power) with typical magnification from 5× to 100×. The eyepiece, also referred to as the ocular, is a convex lens of longer focal length.

2)The image formed in convex lens is always real and inverted except the situation when the object will be placed between focus and optical centre of the lens. At that time, the image will be virtual, erect and highly magnified.

There are two types of images. One is called real image and second one is the virtual image.

Real image can be hold in a plane of paper or screen. The virtual image can not be hold on a screen. It is formed by the rays which are appeared to be coming or intersecting at a point which are either behind a mirror or in front of a lens. That's why virtual images are not drawn on a screen.

option D

A virtual image is formed by convex lens only when the object is placed between focus and lens.

Here object is placed at 20 cm from lens. Hence, the focal length of lens is greater than 20 cm but less than 40 cm.

(c) is correct option

Let distance covered by A be S1Let distance covered by B be S2

B will catch A when S1 = S2S = ut + 1/2 * a * t^2Therefore,

40t + (1/2 * 0 * t^2) = 0t + 1/2 * 4 * t^240t = 2t^220t = t^2

Therefore, t = 20s

no bulb will not lites up and yes bulb gets dimmer if the coil B is moved up

no bulb will not Lite's up And yes bulb gets dimmer if the coil B is moved up.

3) 10√10 m/s is the correct answer

2) right answer good answer

option no. 3 is the correct one

D is the perigee of the orbit.

At D the planet has maximum velocity and therefore maximum Kinetic energy, and minimum potential energy

Hence d is the correct answer

perigee means what

Initially to be put in an orbit around the planet , energy is required in the form of kinetic energy or speed of the satellite.

Once the satellite has sufficient speed, the central force (gravitational force)between the planet and the satellite (weight) acts on the satellite. The effect is that satellite changes direction continuously to move in a circular or elliptic orbit around the planet.

As there is no friction, there is no loss of energy. There is no radiation in this process.Also the gravitational force is conservative.

We know that maximum potential energy=total mechanical energy.

Thus, maximum P.E.=160J.

For calculating the maximum kinetic energy, the formula used is max K.E.=1/2*k*a^2. (and not the usual 1/2*k(a^2-x^2)

So, maximum K.E.=1/2*2x10^6*(0.01^2) which is equal to 100J.

Ans :- a = 0

If a particle is moving with a uniform velocity . Then it's acceleration is Zero .

In passing 2m path against force 100N the. particle will do work and lose KE by the amount 100×2=200 J

So energy of the particle at b will be

800-200=600J

SpecificationforGaugeBlock Comparator. TheGauge Block Comparator shall be used for the calibration ofSlip Gaugesof thickness from 0.5 mm to 100 mm, or more, with an error not exceeding ± 0.02 microns.

thanks a lot for your help

Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.

As body is dropped from a height h, its energy = m g hWhen its comes down through a distance x then its potential energy = m g ( h - x )So KEattained has to be m g x because of conservation of energyGiven PE = 9 * KE==> m g ( h - x) = 9 * m g xSo x =h/10As velocity is to be two times of the velocity attained at this location then newKEwould be 4 * oldKE​Hence KE(New) = 4 * m g x = 4 * m g * h/10OR 2/5 * mg hIf so, then PE = 3/5 m g h (as per conservation of energy)Hence the required ratio of new KE and newPE =2 : 3

Option (a) is correct.

a)electric motor is the spilt ring is used

The speed of any DC motor depends directly on its armature voltage and the strength of its magnetic field. The field winding in a shunt motor is in parallel with the armature winding and the DC supply. If the DC line voltage is constant, the armature voltage will be constant and thus the magnetic field strength will be constant. This consistency leads to a reasonably constant speed of operation.

The speed does tend to drop with increasing load on the motor. This drop in speed is a result of resistive losses in the armature winding. Shunt motors with low armature winding resistance tend to have nearly constant speed of operation.