In a single pass rolling operation, a $$20mm$$ thick plate with plate width of $$100mm$$, is reduced to $$18mm$$ thick. The roller radius is $$250mm$$ and rotational speed is $$10$$ $$rpm.$$ The average flow stress for the plate material is $$300$$ $$MPa.$$ The power required for the rolling operation in $$kW$$ is closer to

A cantilever type gate hinged at $$Q$$ is shown in the figure. $$P$$ and $$R$$ are the centers of gravity of the cantilever part and the counterweight respectively. The mass of the cantilever part is $$75$$ kg. The mass of the counterweight, for static balance, is

A cylindrical container of radius $$R=1$$m, wall thickness $$1$$mm is filled with water upto a depth of $$2$$m and suspended along with its upper rim. The density of water is $$1000$$kg/m³ and acceleration due to gravity is $$10$$ m/s². The self weight of the cylinder is negligible. The formula for hoop stress in a thin walled cylinder can be used at all points along the height of the cylindrical container.

If the Young's modulus and Poisson's ratio of the container material are $$100$$GPa and $$0.3$$, respectively. The axial strain in the cylinder wall at mid height is

A cylindrical container of radius $$R=1$$m, wall thickness $$1$$mm is filled with water upto a depth of $$2$$m and suspended along with its upper rim. The density of water is $$1000$$kg/m³ and acceleration due to gravity is $$10$$ m/s². The self weight of the cylinder is negligible. The formula for hoop stress in a thin walled cylinder can be used at all points along the height of the cylindrical container.

The axial and circumferential stress $$\left( {{\sigma _{a,}}\,{\sigma _c}} \right)$$ experienced by the cylinder wall a mid-depth ($$1$$ m as shown) are