A ball is fixed to spring attached to fixed axle at the centre of a rotating wheel. The ball and spring are constrained to move in the groove shown in figure. Two observers one in rotating frame of the ball and one on the ground at rest observe its motion. Platform is rotating with constant angular velocity and spring has attained its stable configuration. Choose the correct statement(s):
(a) Spring force applies pulling force on the ball radially inward.
(b) Observer on plat-form sees the ball at rest, so centrifugal force balances spring force.
(c) Newton's 1st law is definition of inertial frame and 2nd law is applicable only in inertial frames.