Question

The kinetic energy a pendulum contains when it passes through its zero displacement may be decreased by increasing the mass of the bob. increasing the thickness of the string. decreasing the length of the string.You Answered. increasing the length of the string. decreasing the displacement of the Bob.Correct Answer.

Answer 1

KE that a pendulum contains when it passes thru its 0 displacement 
   = PE that the pendulum has at its extreme positions.
    = m g h   = m g  L (1 - Cos Ф) = m g L * 2 Sin² Ф/2

So  KE increases with increase in m, L or Ф (or h).
KE decreases with decrease in  m , L  or Ф  (or h).