Question

The weight of a man in a lift moving upward is 608 N while the weight of same man in the lift moving downward with some acceleration is 308 N. His normal weight is

• A. 458 N
• B. 588 N
• C. 480 N
• D. 240 N

Answer 1

The correct option is A 458 N

If the lift moving with acceleration $a$.

The weight of a man in a lift moving upward is,

$m(g+a)=608$

$mg+ma=608$. . . . .(1)

The wight of man in a lift moving downward is,

$m(g-a)=308$

$mg-ma=308$. . . . .(2)

Adding equation (1) and (2), we get

$2mg=916$

$mg=458N$

The normal weight of man is $458N$

The correct option is A.