Question
THE MAXm TENn IN STRING OF A SIMPLE PENDULUM IS 1.2TIMES THE MINm TENSION. IF a IS ANGULAR AMPLITUDE THEN a WILL BE
A)cos-1(4/5)
B)COS-1(3/4)
C)cos-1(15/16)
d) cos-1(7/8)
Joshi sir comment
max tension at bottom point = mg+mv2/r
min tension at extreme point = mgcosθ
according to the given condition mg+mv2/r = 1.2mgcosθ (1)
and by energy conservation 1/2mv2 = mg(r-rcosθ) (2)
solve now answer will be C