A 60 kg woman stands on a scale in an elevator. What will the reading on the scale be ise elevator is accelerating downwards at 2.5 m/s^2??

Respuesta :

Because the elevator is going downwards we will use the next formula

[tex]W-T=ma[/tex]

Where W is the weight, T is the tension, m is the mass and a the acceleration.

We can calculate the weight using the next formula

[tex]W=mg[/tex]

where g is the gravity.

We substitute the formula on the first formula and we get

[tex]mg-T=ma[/tex]

We isolate T

[tex]T=mg-ma=m(g-a)[/tex]

We have the next data

m=60 kg

g=9.8 m/s^2

a=2.5m/s^2

We substitute

[tex]T=60(9.8-5)=288N[/tex]

Then we divide between the gravity

[tex]\frac{288}{9.8}=29.4kg[/tex]