A block is placed on the floor of a lift

PHYSICS · Single correct · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics

Problem

5\,\text{kg}

block is placed on the floor of a lift. The lift moves (i) upward with constant speed, (ii) upward with an acceleration of

2\,\text{m}\,\text{s}^{-2}

, (iii) downward with an acceleration of

2\,\text{m}\,\text{s}^{-2}

. In which of these cases is the normal reaction exerted by the floor on the block equal to the weight of the block? (a)

\text{Case (ii) only}

(b)

\text{Cases (i) and (ii)}

(c)

\text{Case (i) only}

(d)

\text{All the three cases}