Most Important Selected Qs for JEE AdvancedPhysicsWork, Power and Energy
Paragraph A small block of mass m , can move without friction on the outside of a fixed vertical circular track of radius R . The block is attached to a spring of natural length R / 2 and spring constant k . The other end of spring is connected to a point at height R / 2 directly above the centre of track. Question If the block is released from rest when the spring is in horizontal state (see figure) then at that mom
Options
- Atangential acceleration is g 3 2 - k R 4 m ( 3 -1)
- Bradial acceleration is g 2 + k R 3 4 m ( 3 -1)
- Ctangential acceleration is g 2 - k R 3 4 m ( 3 -1)
- Dradial acceleration is g 3 2 - k R 4 m ( 3 -1)
Correct answer
A. tangential acceleration is g 3 2 - k R 4 m ( 3 -1)
Step-by-step solution
F_t=m g -k x ; =60^ a_t=g 60^ - k x m 60^ = 3 g 2 - k R 4 m ( 3 -1)a_c=v^2 / r=0 released from rest S.E. = 1 2 k R^2 ( - 1 2 )^2= 1 2 k R^2 ( 3 -1 2 )^2= k R^2 8 ( 3 -1)^2 1 2 m u^2= 1 2 k(R)^2u=R k m