A simple pendulum of length / hangs from the roof of a train moving with uniform acceleration then
in the equilibrium position the pendulum
(a) Leans back from the vertical by an angle tan-1 (g/a)
(b) Leans back from the vertical by an angle tan-1(a/g)
(c) Moves forward from the vertical by an angle tan-1(a/g)
(d) Moves forward from the vertical by an angle tan-1 (g/a)