Practice question
Question
A car moving at 60m/s decelerates uniformly to rest over 150m. What is the time taken to stop?
Explanation
Use v2=v02+2ax to find a: 0=(60)2+2a(150)⇒0=3600+300a⇒a=−12m/s2. 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 5 s as the result, so option D is correct.