Question

Numerically Prove that in oscillating pendulum total energy remains conserved​

Answer 1

At position C & D

P.E = m×g×h

∴ P.E = mgh

K.E = 0 (As Velocity will be 0)

hence total energy = P.E + K.E

= mgh+0

=mgh. ...1

AT POSITION B

P.E = 0 (as height = 0)

v²=u²+2gh

v²=0+2gh

v²=2gh

NOW K.E = ½mv²

K.E = ½×m×2gh

HENCE K.E = 2gh

T.E = mgh + 0 = mgh ...2

Hence Proved