تجــــــمـــع اـلفــيـــــزيـــــــاء ..~

[وعد عبدالله]

17. A man weighing 800 N is standing in an elevator moving with a constant velocity. The force exerted by the man on the floor of the elevator is:
a) less than 80 N b) 800 N c) between 80 and 800 N d) more than 800 N

الجواب 800 ليش ؟؟