Practice question
Question
Two stones are dropped from a height of 80m, 1.5s apart. How long after the second stone is released do they meet if the first rebounds at 15m/s upon hitting the ground? (Take g\=10m/s2)
Explanation
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 4 s. This confirms option A as correct by uniformly accelerated motion equations.