In Q 63 above ,if the elevator moves down with a constant acceleration , the apparent weight of the person is

In Q 63 above ,if the elevator moves down with a constant acceleration

1.	In Q 63 above ,if the elevator moves down with a constant acceleration , the apparent weight of the person is
Answer» less than its TRUE weight equal to its true weight more than its true weight more or less than its true weight Solution :Whena PERSON of MAAS M is standing on a weighing machine placed in a LIFT , the actual weight of the person =Mg This weight acts on the weighing machine which offers a reaction R, given by the reading of the weighing machine. (i)When the elevator is at rest or moving with UNIFORM velocity , upwards or downwards , apparent weight R = mg , which is the actual weight . (ii)When the elevator is accelerating downwards with acceleration a , we have mg - R =ma or R= m(g-a) In this case , apparent weight becomes less. (iii) When the elevator is accelerating upwards with acceleration a , we have R- mg=ma or R=m(g+a) In this case , apparent weight becomes more . (iv)If a=g,R=m(g-g)=0 So , the apparent weight of a person in an elevator falling down freely with an acceleration (=g) is zero .