The pendulum shown in the figure is kept horizontal. It is released from this positions. What is its velocity when it reaches the lowest position? `(g=9.8ms^(-2))`

Answer

`7ms^(-1)`

Explanation

Kinetic energy at position B
= potential energy at position A
`(1)/(2)mv_(max)^(2)=mgh`
`therefore v_(max)^(2)=2gh`
`therefore v_(max)=sqrt(2gh)`
`therefore` Maximum velocity of pendulum,
`v_(max)=sqrt(2xx9.8xx2.5)`
`=sqrt(49)`
`=7ms^(-1)`