ans)
from above data that
The Time period of the pendulum
      T = 2π √ [ L/g
]
        Â
= 2π √[0.84 /9.8 ]
        Â
=1.84 s
The angular frequency is
       ω= 2π /
T
            =2
Ï€ / 1.84
           =
3.41 rad/ s
The height through which the bob is lifted up
is
       h = L ( 1
- cosθ )
         Â
=0.84 ( 1 - cos 9.05)
         Â
=0.0104 m
The total mechanical energy is
       E = m g
h
         Â
=0.23(9.8)0.0104 m
         Â
=2.34 x10-2J
When the bob passes through the lower position, the
energy iscompleted in the form of kinetic energy
  0.5*m*v²;
v = √[2*KE/m] = √[2*0.0234/0.23] = 0.461 m/s
