Q.

A simple pendulum with length 100 cm and bob of mass 250 g is executing S.H.M. of amplitude 10 cm. The maximum tension in the string is found to be x40 N. The value of x is ________ .              [2023]


Ans.

(99)

sinθc=Al=10100=110

From conservation of energy:

12mv2=mgl(1-cosθ)

Maximum tension occurs at mean position.

 T-mg=mv2l  T=mg+mv2l

 T=mg+2mg(1-cosθ)

=mg[1+2(1-1-sin2θ)]=mg[3-21-1100]

=2501000×9.8[3-2(1-1200)]=9940

 x=99