[relativistic]

THIS IS THE ANSWER

WE CAN START FROM THE POINT THAT
THE ACCELERATION OF PENDULUM AT A POINT IN ITS DIRECTION OF MOTION {A} EQUALS THE VERTICAL ACCELERATION {g}MULTIPLIED BY COSINE THE ANGLE {X} BETWEEN THE DIRECTION OF MOTION OF PENDULUM AND THE VERTICAL LINE

SO
A= g * Cos X

SO THE VELOCITY OF THE PENDULUM IS THE INTEGRATION OF THE ACCELERATION FROM THE START POINT TILL THE END POINT
{WE HAVE TO NOTE THAT THE ANGLE BETWEEN DIRECTION OF MOTION OF PENDULUM AND THE VERTICAL EQUALS THE ANGLE BETWEEN THE LINE OF THE PENDULUM AND ITS RESTING POSITION}
SO WE WILL USE THE LAST DEFINITION OF X AS THE ANGLE BETWEEN THE LINE OF THE PENDULUM AT ANY POINT AND THE LINE OF PENDULUM AT REST

X CHANGES FROM -30 TO 0
SO VELOCITY AT RESTING POSITION HERE IS
V = g Sin 30 = 5 M/SEC. IF g=10 M / SEC^2

TELL ME IF THIS STEP IS RIGHT