A particle's motion obeys t = √x + 3, with t in seconds and x in metres. Find the first time at which the particle is at rest.
Physics · Mixed Chapter
JEE Main Practice

Question

A particle's motion obeys t = √x + 3, with t in seconds and x in metres. Find the first time at which the particle is at rest.

G1 Physics · Accepted Answer

Step 1: Rearranging, √x = t−3 and x = (t−3)² for t ≥ 3 s. Step 2: Differentiate: v = dx/dt = 2(t−3). Step 3: At rest, v = 0 ⇒ t = 3 s.