Statement-I : An elevator can go up or down with uniform speed when its weight is balanced with the tension of its cable. Statement-II : Force exerted by the floor of an elevator on the foot of a person standing on it is more than his/her weight when the elevator goes down with increasing speed. In the light of the above statements, choose the correct answer from the options given below :
(A)Both statement I and statement II are false
(B)Statement I is true but Statement II is false✓ Correct
(C)Both Statement I and Statement II are true
(D)Statement I is false but Statement II is true
Answer: (B)
Solution
Moving up or down at a uniform speed means zero acceleration, so the net force on the lift vanishes and the cable tension exactly balances its weight; the first statement is sound. When the lift descends with increasing speed its acceleration points downward, and the floor reaction on the person follows N=m(g−a), which is smaller than the true weight rather than larger. The first statement is true and the second is false.
JEE Main · 2023 · 24 Jan 2023 · Shift 1 · Single correct option
