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

In Q 63 above , if the elevator moves upward with a constant accelerat

1.	In Q 63 above , if the elevator moves upward with a constant acceleration , the apparent weight of the person is
Answer» less than his true weight equal to his true weight more or less than his true weight more or less than his 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 .