A 9kg block is pushed with 45N over 7m on a frictionless surface, starting from rest. What is its final speed?
Work W=45×7=315J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 8 m/s. This satisfies dimensional consistency and physical conditions given, so option A is scientifically correct.
Ref: NCERT Class 11 Physics > Chapter 6: Work, Energy and Power > Topic: Work, Energy and Power - Work-Energy Theorem
