What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it…

What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop?
  1. gR
  2. 2gR
  3. 3gR 
  4. 5gR

Solution

Let velocity at the lowest point is "u" and velocity at the top most point is "v"

At highest point  mv2R=mgv=gR
now  v 2 = u 2 2g( 2R ) u 2 =5gR
Minimum velocity required is u=5gR

Asked in: NEET 2016 (Phase 1)

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