A person weighs 150 pounds. He is standing on a scale inside an elevator. If the elevator is free-falling downward (perhaps the cable broke), what is the reading of the scale?

150 pounds

about 25 pounds

0 pounds

not enough info

Total force on person = m g = m a in free fall. No external force on person from scale

so 150?

No !!! ZERO no force on scale - in free fall, accelerating downward at 9.81 m/s^2

Like - "weightless" :)

Backup link :)

http://www.jiskha.com/display.cgi?id=1282164495

Oh so 0 pounds :)

Yes 0

free falling
weightless :)