A stone is dropped from a height of 122.5m. How long does it take to reach the ground? (Take g\=10m/s2)
For free fall, s=½gt² and v²=2gh per NCERT. With g=10 m/s², given height or velocity yields time or distance via these equations. Substituting values gives result matching 5 s. This confirms option A as correct by uniformly accelerated motion equations.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Uniform Acceleration and Graphical Analysis