Figure below shows a wheelbarrow of mass $15 \mathrm{kg}$ carrying a load of $30 \mathrm{kgf}$ with its centre of gravity at $A$. The points $B$ and $C$ are the centre of wheel and tip of the handle such that the horizontal distance $AB=20 \mathrm{cm}$ and $AC=40 \mathrm{cm}$.

Calculate: (i) the load arm, (ii) the effort arm, (iii) the mechanical advantage and (iv) the minimum effort required to keep the leg just off the ground.

For a given height h, _____the length of the inclined plane, lesser will be the effort required.

A box of mass $30 \mathrm{kg}$ is to be raised from ground to a platform at P. A boy A does it by pushing the box along the slope QP of length$\mathrm{x}$, while another boy B does it by using the slope RP of length$\mathrm{y}$. Ignoring the force of friction, compare the effort applied by the boys A and B.

A box of mass $30 \mathrm{kg}$ is to be raised from ground to a platform at P.  A boy A does it by pushing the box along the slope QP of length$x$, while another boy B does it by using the slope RP of length$y$. Ignoring the force of friction, compare the work done by the boys A and B.