A lift is moving upwards with an ac...
Question

# A lift is moving upwards with an acceleration of 2 m/sec?. When the upward velocity of the lift is 5m/sec, a particle is projected vertically upwards with a velocity of 3 m/sec. with respect to the floor of the lift by a passenger. Find the time after which it reaches the passenger again (B)' sec. (A) (c) Allwin sec sec. (D) 1 sec.

JEE/Engineering Exams
Physics
Solution
186
1.0 (1 ratings)
The relative ueloisty between the cole and the puticle is ( 5+3 ) -5 ( =3 ) mis poiticle will have ( g=left(0 mathrm{m} / mathrm{s}^{2} ) doumudel right. Now relatuu alceleralion of particle abont the ift is ( -10-2=-12 mathrm{m} / mathrm{s}^{2} ) suppore paiticle uomes back is afler timet then ( u t^{prime}+frac{1}{2} a t^{2}=0 ) [ 3 t-frac{1}{2} x^{2}+2 x t^{2}=0 ] ( vec{t}=frac{6}{12}=0.5 mathrm{sec}=frac{1}{2} mathrm{sec}= ) option ( (B) )