A person in an elevator accelerating upwards with an acceleration of 2 m s^–2, tosses a coin vertically upwards with a speed of 20 m s^-1. After how much time will the coin fall back into his hand? ( g = 10 m s^–2)

<p><span lang="EN-IN">This is a Short Answer type Questions as classified in NCERT Exemplar</span></p><p><strong><span lang="EN-IN">Explanation -</span></strong><span lang="EN-IN">initial speed of coin u= 20m/s</span></p><p><span lang="EN-IN">Acceleration of elevator =2m/s² acceleration due to gravity = 10m/s²</span></p><p><span lang="EN-IN">Effective acceleration =g+a=12m/s²</span></p><p><span lang="EN-IN">We know that v=u +at</span></p><p><span lang="EN-IN">0= 20+ (-12)t</span></p><p><span lang="EN-IN">So t= 20/12=5/3 s</span></p><p><span lang="EN-IN">Time of ascent = time of descent </span></p><p><span lang="EN-IN">Total time coin fall back into hand = (5/3+5/3)=10/3s=3.33s<strong> </strong></span></p>

0 Upvotes 0 Upvotes 0 Downvotes

• • Report Abuse
• Comment