- #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"?