Work Energy and...

A uniform chain of length $$2$$ m is kept on a table such that a length of $$60$$ cm hangs freely from the edge of the table. The total mass of the chain is $$4$$ kg. What is the work done in pulling the entire chain on the table? 

A point starts from rest and moves along a circular path with a constant tangential acceleration. After one rotation, the ratio of its radial acceleration to its tangential acceleration will be equal to:

A block 'A' of mass 2m placed on another block 'B' of mass 4m which in turn is placed on a fixed table. The two blocks have the same length 4d and they are placed as shown in the figure. The coefficient of friction (both static and kinetic) between block 'B' and table is $$\mu $$. There is no friction between the two blocks. A small object of mass m moving horizontally along a line passing through the centre of mass (CM) of block B and perpendicular to its face with a speed v collides elastically with block B at a height d above the table. What is the minimum value of v required to make the block A topple?

A force acts on  a $$30$$ gm particle in such a way that the position of the particle as a function of time is given by $$x = 3t - { 4t }^{ 2 } + { t }^{ 3 }$$, where $$x$$ is in meters and $$t$$ is in seconds. The work done during the first $$4$$ second is :-

Under the action of variable force, at any instant the displacement is

A road is banked at an angle of $$37^{ 0 }.$$ If a car moving at 54 km/hr does not experience any friction force while negotiating the curve, the radius of curve is :-

A bullet of mass m strikes a pendulum bob of mass M with velocity u. It passes through and emerges out with a velocity u/2 from bob. The length of the pendulum is l. What should be the minimum value bob u if the pendulum bob will swing through a complete circle?

A particle is whirled in a vertical circle of radius 1.0 m using a string with one end fixed. If the ratio of maximum and minimum tension in the string is $$\frac{5}{3}$$, the minimum velocity of the particle during circular motion is : 

A simple pendulum has length l. The minimum velocity to be pendulum so that it performs vertical circular motion is

A man raises 1 kg wt. to a height of 100 cm and holds it there for 30 minutes. How much work has he performed?