Practice question
Question
A ball is thrown horizontally at 15m/s from a height of 98m. What is its horizontal range? (Take g\=9.8m/s2)
Explanation
Time to fall: h=12gt2⇒98=12×9.8×t2⇒98=4.9t2⇒t2=20⇒t=20≈4.47s. 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 60 m as the result, so option A is correct.