A rope is used to lower vertically a block of mass $M$ by a distance $x$ with a constant downward acceleration $\frac{g}{2}$. The work done by the rope on the block is

A body of mass $m$ is moving in a circle of radius $r$ with a constant speed $u$. The force on the body is $mv^2/r$ and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle?

A particle moves along $x$-axis from $x=0$ to $x=5$ metre under the influence of a force $F=7-2 x+3 x^2$. The work done in the process is .............

A particle moves with a velocity $\vec v\, = \,5\hat i - 3\hat j + 6\hat k\,\,m/s$ under the influence of a constant force $\vec F\, = \,10\hat i + 10\hat j + 20\hat k$. Instantaenous power will be ............... $\mathrm{J} / \mathrm{s}$

The total work done on a particle is equal to the change in its kinetic energy. This is applicable

The kinetic energy $K$ of a particle moving in a straight line depends upon the distance $s$  as $K = as^2$. The force acting on the particle is