- #1

Sunwoo Bae

- 60

- 4

- Homework Statement
- A 65 kg woman descends in an elevator that briefly accelerates at 0.20 g downward. She stands on a scale that reads in kg. During this acceleration, what is her weight and what does the scale read?

- Relevant Equations
- Use Weight= mass*gravitational acceleration and F= ma

Fn= normal force

W=mg

W=(65)(9.8)= 637N

Fn-637= -(65)(0.2*9.8)

Fn= 509.6N

I got the weight of the woman in the elevator, but I have trouble finding what the scale reads in kg. I was given the solution which read:

a = (g-0.2g)= 0.8g

W= 0.8g*509.6N= 52kg.

My questions

1. why do I have to subtract 0.2g from 1g?

2. Why don't they substitute gravitational constant(9.8m/s^2) in "g"?

W=mg

W=(65)(9.8)= 637N

Fn-637= -(65)(0.2*9.8)

Fn= 509.6N

I got the weight of the woman in the elevator, but I have trouble finding what the scale reads in kg. I was given the solution which read:

a = (g-0.2g)= 0.8g

W= 0.8g*509.6N= 52kg.

My questions

1. why do I have to subtract 0.2g from 1g?

2. Why don't they substitute gravitational constant(9.8m/s^2) in "g"?