Bread mould is name of 

A rope is wrapped several times around a uniform solid cylinder of radius 0.1 metre and of mass 50 kg , pivoted so it can rotate about its axis. What is the angular acceleration (rad`s^-2`) when the rope is pulled with the force of 20 Newton ?

Bread mould is name of 

A vertical wire fixed at one end is stretched by a load of 20 Newton at the lower end the extension is `3**10^- is3\ m`,  is the cross sectional area of the wire is `2**10^-6\ m^2`,  and the original length of the wire is 2 metre.  Asssuming Hookes law to hold, the molecular potential energy of the stretched wire is