(d) $v = \sqrt{49 + y},a = \frac{dv}{dy}.\frac{dy}{dt} = v\frac{dv}{dy}$ $= (49 + y)^{1/2} \times \frac{1}{2}(49 + y)^{1/2 - 1}$= $\frac{1}{2}ms^{- 2}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.