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  • 2 answers

Raunak Chauhan 4 years, 9 months ago

Shake is the smallest unit of time

Krishna Shah 4 years, 9 months ago

The unit of time is 'second'.
  • 0 answers
  • 1 answers

Gaurav Seth 4 years, 9 months ago

 

For mechanical equilibrium of a rigid body, two conditions need to be satisfied:

1. Translational equilibrium: The net external force or the vector sum of all the external forces acting on the body must be zero.i.e 

2.Rotational equilibrium :The net external torque or the vector sum of all the torques acting on the body is zero.

i.e 

  • 4 answers

Abirami Kamalbabu 4 years, 9 months ago

A body which observes radiations of different frequencies uniformly is called black body. The radiation emitted by such a body is called black body radiation. Practically no perfect black body exist. But carbon black is nearly close to a black body.

Raunak Chauhan 4 years, 9 months ago

The body which can prefactly absorb and emit radiation is called a black body . In nature there is no existence of black body which can prefactly emit and absorb radiation. The radiation emitted by a black body is called black body radiation

Sruti Mohanty 4 years, 9 months ago

The emission radiated by a black body is called black body radiation. A body which can absorb all the radiations of variable wavelengths is called black body

Gaurav Seth 4 years, 9 months ago

Black body radiation: Black body is defined as perfect emitter and absorber of light.
For example, whenever we heat an Iron ball like objects, on heating they become first Red, then Orange, then Yellow and at very high temperature they become White.

According to the electromagnetic theory, the energy is emitted or absorbed continuously. So, the radiations emitted may vary in intensity, but should have same colour. The change in color shows, that wavelength also changes .This indicates non continuous flow of energy. So, it couldn’t be explained by electromagnetic theory. This phenomenon shows, that if we keep on heating the light that it emits. It will show changes in wavelength. That means the wavelength keeps on decreasing but after White there is no further change.

  • 3 answers

Apurva Jindal 4 years, 9 months ago

For me many year like 1935 in this small pox spread and world's 40 percent population die in this case what could you say.....that 2020 is worst orr any other year is worse....this system of allegations can go so far....but we can do something is that allegations and something which heals the situation.....we have do our best help others by taking all precautions and heals others........This all that I have to say but not only 1935 or 2020..so many other year also passed...but by novel deeds it was heel....so do good things and help others......Thank you

First Name 4 years, 9 months ago

Some crazy and stupid people like one of them here (I wont say his name), if they would exist, forget the environment will not do anything!

First Name 4 years, 9 months ago

Better stop enjoying and improve ourselves . Start taking care of environment , otherwise... hard to tell how it will take its revenge from humans!
  • 5 answers

Navjot Kaur 4 years, 9 months ago

U2

?Ritesh Gupta? 4 years, 5 months ago

Same 2u aadu

Aryan Raj 4 years, 9 months ago

U 2

Gaur Saab?? 4 years, 9 months ago

^_^

Dhruv ... 4 years, 9 months ago

????
  • 1 answers

Yogita Ingle 4 years, 9 months ago

In a chemical reaction chemical equilibrium is defined as the state at which there is no further change in concentration of reactants and products.
For example,

At equilibrium the rate of forward reaction is equal to the rate of backward reaction. Equilibrium mixture: The mixture of reactants and products in the equilibrium state is called an equilibrium mixtures.
Based on the extent to which the reactions proceed to reach the state of equilibrium, these may be classified in three groups:
(i) The reactions which proceed almost to completion and the concentrations of the reactants left are negligible.
(ii) The reactions in which most of the reactants remains unchanged, i.e. only small amounts of products are formed.
(iii) The reactions in which the concentrations of both the reactants and products are comparable when the system is in equilibrium.

  • 3 answers

Śěřãj The Cute? 4 years, 9 months ago

Mai seraj???????

Śěřãj The Cute? 4 years, 9 months ago

Hello royal bhai kaise ho

Gaurav Seth 4 years, 9 months ago

Projectile Motion

When any object is thrown from horizontal at an angle θ except 90°, then the path followed by it is called trajectory, the object is called projectile and its motion is called projectile motion.

If any object is thrown with velocity u, making an angle θ, from horizontal, then

  • Horizontal component of initial velocity = u cos θ.
  • Vertical component of initial velocity = u sin θ.
  • Horizontal component of velocity (u cos θ) remains same during the whole journey as no acceleration is acting horizontally.
  • Vertical component of velocity (u sin θ) decreases gradually and becomes zero at highest point of the path.
  • At highest point, the velocity of the body is u cos θ in horizontal direction and the angle between the velocity and acceleration is 90°.


Important Points & Formulae of Projectile Motion

  1. At highest point, the linear momentum is mu cos θ and the kinetic energy is (1/2)m(u cos θ)2.
  2. The horizontal displacement of the projectile after t seconds
    x = (u cos θ)t
  3. The vertical displacement of the projectile after t seconds
    y = (u sin θ) t — (1/2)gt2
  4. Equation of the path of projectile
  5. The path of a projectile is parabolic.
  6. Kinetic energy at lowest point = (1/2) mu2
  7. Linear momentum at lowest point = mu
  8. Acceleration of projectile is constant throughout the motion and it acts vertically downwards being equal to g.
  9. Angular momentum of projectile = mu cos θ x h, where h denotes the height.
  10. In case of angular projection, the angle between velocity and acceleration varies from 0° < θ < 180°.
  11. The maximum height occurs when the projectile covers a horizontal distance equal to half of the horizontal range, i.e., R/2.
  12. When the maximum range of projectile is R, then its maximum height is R/4.
  • 1 answers

Yogita Ingle 4 years, 9 months ago

Lets consider a body is acted by the variable force

  • 1 answers

M. Pranathi 4 years, 9 months ago

Both the net force and net torque must be zero
  • 2 answers

Monu J 4 years, 9 months ago

Pru

Gaurav Seth 4 years, 9 months ago

a ns w  e r
Energy is involved in a chemical change because of formation and breakdown of bonds. In exothermic reactions energy is released and in endothermic reactions energy is taken in.

  • 1 answers

Gaurav Seth 4 years, 9 months ago

Weak Nuclear Force: This force appears only in certain nuclear processes such as the β-decay of a nucleus. In β-decay, the nucleus emits an electron and an uncharged particle called neutrino.This particle was first predicted by Wolfgang Pauli in 1931.

  • 3 answers

Mohd Zuaib 4 years, 9 months ago

4.8 g/cm³

Yogita Ingle 4 years, 9 months ago

Density = Mass/Volume  = 5.74/1.2 = 4.783 g/cm3 
Here least significant figure is 2,
so density = 4.8 g/cm3 

Chundawat 4001 Singh 4 years, 9 months ago

4.8g cm-3
  • 5 answers

Gagandeep Kaur 4 years, 9 months ago

When more than one forces are balanced by each other such that they produce no effect,are said to be in equilibrium

?Ritesh Gupta? 4 years, 9 months ago

??

Dhruv ... 4 years, 9 months ago

Aadya agent??

Aadya Singh 4 years, 9 months ago

Shut up! ?

Dhruv ... 4 years, 9 months ago

Dalli aadya??☺️☺️
  • 2 answers

First Name 4 years, 9 months ago

L = length of wires
Y = Young's modulus of wires
R1= r
R2=2r
As equal elomgation is produced,
∆l = elongation
F = YA∆l/l
f = YA'∆l/l

F/f = A/A'
F/f = $$\pi$$r²/$$\pi$$r² ×4
F:f = 4 : 1

Snehil J@@T 4 years, 8 months ago

Itne questions
  • 1 answers

Yogita Ingle 4 years, 9 months ago

it is based on Young's modulus concepts .

we know, Young's modulus = stress/strain
stress = F/A , strain = ∆L/L

so, Young's modulus, Y = FL/A∆L
so, F = YA∆L/L
hence, it is clear that tension in rope is directly proportional to area of cross section of rope.

area of cross section of rope , A = πd²/4

so, 
we can write , 

so, 



hence, maximum tension that may be given to a similar role of diameter 2cm is 2000N

  • 2 answers

First Name 4 years, 9 months ago

2 and 4

Gaurav Seth 4 years, 9 months ago

(4)

not accelerating .

Reason:

Forces that are equal in size but opposite in direction are called balanced forces. Balanced forces do not cause a change in motion. When balanced forces act on an object at rest, the object will not move. If you push against a wall, the wall pushes back with an equal but opposite force

  • 2 answers

Abirami Kamalbabu 4 years, 9 months ago

Acceleration comes into play only if the body is moving non-uniformly . Otherwise it is zero. Here the body is moving uniformly. So zero acceleration.

Yogita Ingle 4 years, 9 months ago

Acceleration of a body moving with a uniform velocity = 0

 because acceleration = change in velocity​/time

 change in velocity= 0

SO, acceleration = 0

  • 4 answers

Gaur Saab?? 4 years, 9 months ago

Naa veere Maine nhi suna iska name

Ankit B 4 years, 9 months ago

Ankit Bhandari is a hero

Gaurav Seth 4 years, 9 months ago

Earth attracts all things towards it through an unseen force of attraction. This force of attraction is called as gravitation or gravitational pull. You must have noticed that every time you throw an object upwards, it reaches a certain height and then falls down on the earth's surface

Nisha Gothi 4 years, 9 months ago

Whar is force
  • 1 answers

Gaurav Seth 4 years, 9 months ago

Using S = ut + (1/2)at²

 

S = 500 m

u = 0   Start from rest

a = ?

t = 30 sec

 

=> 500 = 0 + (1/2)a(30)²

=> a = 1000/900

=> a = 10/9  m/s²

 

V = u + at

=> V = 0 + (10/9) * 30

=> V = 100/3 m/s

 

velocity of the aeroplane at the take off​ = 100/3 m/s

  • 1 answers

Yogita Ingle 4 years, 9 months ago

We know that, distance = speed×time

So, d = 50×40 = 2000m

d = 2×3.14×r (circumference of the circle)

=> 2000=2×3.14×r

On calculating, r = 318.47 m

In this case, required acceleration will be centripetal acceleration.

So, a = (v×v)/r

        a = (50×50)/318.47

        a = 7.85m/s^2

 

  • 2 answers

Yogita Ingle 4 years, 9 months ago

When a particle is thrown obliquely near the earth’s surface, it moves along a curved path under constant acceleration that is directed towards the center of the earth (we assume that the particle remains close to the surface of the earth). The path of such a particle is called a projectile and the motion is called projectile motion. Air resistance to the motion of the body is to be assumed absent in projectile motion.

In a Projectile Motion, there are two simultaneous independent rectilinear motions:

  1. Along the x-axis: uniform velocity, responsible for the horizontal (forward) motion of the particle.
  2. Along y-axis: uniform acceleration, responsible for the vertical (downwards) motion of the particle.

Nazaf Parveen 4 years, 9 months ago

When any object is thrown from horizontal at an angle theta except 90° , then the path followed by it is called trajectory, the object is called projectile and it's motion is called projectile motion.
  • 2 answers

Jadav Narendra 4 years, 9 months ago

Dffrr

Gaurav Seth 4 years, 9 months ago

The expression for rigid body’s “rotational kinetic energy” is 

SOLUTION:

A body undergoing a rotational dynamics with angular velocity ω will also poses a translational motion. Let the velocity for translation motion be ‘’v’’.

We know for translational motion the energy poses by body is kinetic and given as

Also we know that for a body obeying rotation  

v=rω

Substituting in translation

Also there is a relation for moment of inertia i.e 

Substituting we get,

 

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