Practice question
Question
A 4kg block slides down a frictionless incline from a height of 3m. What is its speed at the bottom? (Take g\=10m/s2)
Explanation
Potential energy mgh=4×10×3=120J. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 7 m/s. This satisfies dimensional consistency and physical conditions given, so option A is scientifically correct.