A stone is thrown horizontally at 20m/s from a height of 45m. What is its time of flight? (Take g\=10m/s2)
Vertical motion: y=12gt2, where y=−45m. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 3 s as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Motion Parameters and Calculations