A runner moving at 7m/s throws a ball horizontally at 14m/s relative to himself. If it lands 21m ahead of the throw poin
Ball’s speed relative to ground = 7+14=21m/s. 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 21 m/s as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Motion in a Straight Line - Advanced Problems