A block of mass m is at rest relative to a rough incline kept inside an elevator moving upward with acceleration a. Which statement is correct?

Question

G1 Physics · Accepted Answer

In the inertial frame the block accelerates vertically upward with the elevator. Therefore the resultant of normal plus friction must combine with mg to give ma upward. Hence the total contact force from the incline is vertical upward, with magnitude m(g+a). Only statement A is correct.