Question

Elizabeth. mass=60.0 kg stands on a scale in an elevator. mass of elevator plus Elizabeth= 700 kg. as the elevator moves, the scale reads 500N. Find the tension in the cable.

Answer 1

Here we have given that,

mass m =60.0 kg

Mass of elevator plus Elizabeth mt = 700 kg

So that total reading should be here will be,

W = 700×9.8 = 6860 N

Also Here its given that,

elevator moves and the scale reads 500N

Means here the reading of the scale is less than the actual weight of the elevator and Elizabeth.

-500+60×9.8 = 60×a

a = (1.4667 m/s²)

Now using the condition of summation of forces here we will get,

Mtg - T = Mta

So that on plugging the values here,

T = Mt(g-a) = 700× (9.8-1.4667)

T = 5833.331 N

Which is the required tension in the cable.