
https://www.youtube.com/watch?v=Z47IRtuF0eI ...

An excited atom of mass m and initial speed v emits a photon in its direction of motion. If v << c, show that the frequency of the photon is higher by \frac{\Delta f}{f} \approx \frac vc , than it would have been if the ...

q) Given k1 = 1500 N/m, k2 = 500 N/m , m1 = 2kg and m2 = 1kg. Find (a) potential energy stored in the springs in equilibrium, and (b) work done in slowly pulling down m2 by 8cm. *Image* the image is not clear i knw... but jus ...

Consider a case when a block is placed on a horizontal platform at rest. It then starts accelerating with a constant acceleration such that, Friction present between the block and the horizontal platform > mass times its a ...

q) A chain is held on a frictionless table with (1/n)th of its length hanging over the edge. If the chain has a lenth L and mass M, how much work is required to slowly pull the hanging part back on the table? ...

In a stationary wave that forms as a result of reflection of waves from an obstacle the ratio of the amplitude at an antinode to the amplitude at node is K. Find the percent of Total Energy reflected. ...

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*Image* A force F acts on a block of mass m placed on a horizontal smooth surface at an angle Θ with horizontal. Then (A) If F sinΘ < mg then a = F + mg/m (B) Acceleration = FCosΘ/m when F > mg cosecΘ (C) Accelerati ...

What to do and what not to do in the last month before IITJEE http://www.youtube.com/watch?v=Z5AfiJxjOc&context=C4acfebbADvjVQa1PpcFMQXFKsRHXxJDA7RTt_k4sN1NL6Iapsuo= ...

Consider a rod CD which is held horiznotally across a peg transversally .(something like a a st line abt a peg and free to rotate abt any pnt)bt point A(which is not the com) and D is the com . and DA=a Find the angle rotated ...

if a body is rotating in a circular orbit then what is the moment of net force acting on the body about the axis of rotation? ...

Two uniform, thin identical rods each of mass 'm' and length 'l' are joined to form a cross as shown in the figure. Find the moment of inrtia of the cross about a line AC. (Which is perpendicular to the plane of paper passing ...

This is a marathon for Physics ie., IT continues for long. A user posts problem, the next posts the solution and ANOTHER problem to be solved by the subsequent one and this Continues. Problem 1 A uniform rod of length *Image* ...

q) Two particles, each of mass m and speed v, travel in opposite directions along parallel lines separated by a distance d. Show that the vector angular momentum of the two particles system is the same whatever be the point a ...

*Image* A projectile is fired at t=0 with velocity v = 20√2 m/s at an angle of 45° degrees as shown. A wall inclined at the same angle and at a distance of 40 m starts moving towards the projectile at the same time (ie., t ...

1) NCERT says in some cases the angular momentum of a particle may not be parallel to the fixed axis. Can you give an example? In case of rotation about fixed axis, the component of angular momentum perpendicular to the fixed ...

2 persons are holding a rope of negligible weight tightly at its ends,so that it is horizontal. A 20kg weight is attached to the rope at the midpoint,which is now no longer horizontal. The minimum tension required to strengt ...

What are the forces acting on the ladder in the example below *Image* The ladder is held against the wall, the wall is frictionless. So what will be the fores acting on the ladder? please help...........!! ...

The vibation frequency of atoms in solid at normal temperature are of the order 1013/sec. Imagine the atoms to be connected by springs... Suppose that a single silver atom vibrates with this frequecy and that all other atoms ...

Q: Why is easier to break a piece of paper that you wet dry? ...

Mechanics: *Image* The coefficients of friction are μs = 0.40 and μk = 0.30 between all surfaces of contact. Determine the force P for which motion of the 30kg block is impending if cable AB (a) is attached as shown, (b) i ...

A mass 'm' is undergoing S.H.M. in the vertical direction about the mean position 'x' with amplitude 'A' and angular freq. \omega . At a distance y from the mean position, the mass detaches from the spring. Assuming that the ...

A straight conductor of uniform crosssection carries a current I. Let 'S' be the specific charge of an electron. The momentum of all the free electrons per unit length of the conductor, due to their drift velocities only, in ...

A block of mass 'M' executes S.H.M. with amplitude 'A'. When it passes through the mean position, a lump of putty of mass 'm' is dropped on it.Find the new amplitude. ...

A SPHERE OF RADIUS 'R' IS FLOATING IN A LIQUID OF DENSITY '\rho ' WITH HALF OF ITS VOLUME SUBMERGED. IF THE SPHERE IS SLIGHTLY PUSHED AND RELEASED, IT STARTS PERFORMING S.H.M. FIND THE FREQUENCY OF THESE OSCILLATIONS. ...

*Image* i am getting c) but ans. given is d) ...

NCERT question number 36. chapter  laws of motion. ...

*Image* Consider a mass ' m ' rotating about the given axis with angular velocity ' ω '. Find the acceleration and Pseudo Force of the block as seen from the MID POINT of the string. Assume the length of string as ' L '. ...

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