A particle is observed from frames two S1 and S2 . The frame S2 moves with respect to S1 with an acceleration a.Let F1 and F2 be the pseudo forces on the particle when seen from S1 and S2 respectively. Which of the following are not possible ?

(d) is the correct answer. Accelerations are the result of forces acting upon bodies. Since S1 and S2 do not have the same accelerations, the forces F1 and F2 cannot be the same; selections (a) thru (c) are all vague, but that vagueness means that the forces and accelerations in each case can or explicitly are different, meaning (d) is the one case which is not possible.