Q 11-05-171JEE MainJEE Main 2020 (3 Sep, Shift 2)Medium
A particle is moving unidirectionally on a horizontal plane under the action of a constant power supplying energy source. The displacement $(s)$ – time $(t)$ graph that describes the motion of the particle is (graphs are drawn schematically and are not to scale):
Answer: (B) Graph (B)
With constant power $P$ starting from rest: $Pt = \tfrac12mv^{2} \Rightarrow v = \sqrt{\dfrac{2Pt}{m}} \propto t^{1/2}$.
Integrating, $s \propto t^{3/2}$: the $s$–$t$ graph starts at the origin and curves upward (slope increasing), as in graph (B).
Solution by Sreeraj P, M.Sc Physics