Work Energy and...

In a vertical circle of radius $$(r)$$, at what point in its path a particle may have tension equal to zero:

A stone attached to one end of a string is whirled in a vertical circle. The tension in the string is maximum when

A position dependent force $$F=7-2x+3x^{2}$$N acts on a small object of mass 2kg to displace it from $$x=0$$ to $$x=5m$$. The work done in joules is-

A particle is moving in a vertical circle, the tension in the string when passing through two position at angle $$30^{\circ}$$ and $$60^{\circ}$$ from vertical from lowest position are $$T_1$$ and $$T_2$$ respectively, then 

A pendulum bob has a speed $$3\;m/s$$ while passing through its lowest position, length of the pendulum is $$0.5\;m$$ then its speed when it makes an angle of $$60^{\circ}$$ with the vertical is

A particle slides from rest from the topmost point of a vertical circle of radius ($$r$$) along a smooth chord making an angle $$(\theta)$$ with the vertical the time of decent is 

A particle of mass $$m_{1}$$ moving with a velocity of $$5m/s$$ collides head on with a stationary particle of mass $$m_{2}$$. After collision both the particle move with a common velocity of $$4m/s$$, then the value $$m_
{1}/m_{2}$$ is:

Under the action of a force, a 2kg mass moves such that its position x as a function of time t is given by $$x=t^3/3$$ where x is in meters and t in second. The work done by the force in first two seconds is:

Force shown acts for $$2$$ seconds. Find out work done by force $$F$$ on $$10$$ kg in $$3$$ seconds.

A time dependent force F = 10 t is applied on 10 kg block. Find out the work done by F in 2 seconds.