Is it a violation of the second law of thermodynamics to

Solution 6DQ Step 1: It is possible to completely convert the mechanical energy into heat. But, we cannot completely convert the complete heat of the system into useful work. If we are applying mechanical energy into a system, the mechanical energy will be converted to thermal energy. If thermal energy increases, the temperature increase and heat will be added to the system. So, we can convert the mechanical energy completely into heat without violating the second law of thermodynamics.