1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

NSO class 9th

  1. Oct 21, 2015 #1

    faiziqb12

    User Avatar
    Gold Member

    • Warning: Homework template must be used and some solution attempt made.
    A problem came in the previous years Olympiad ::

    if we go inside a mine and drop 10 lb iron ball and 1 lb allumunium ball from top of a high platform, then
    1. both will reach the ground at same time
    2. 1 lb weight will reach the floor first
    3. 10 lb weight will reach the floor first
    4. incomplete data

    the answer is 1

    but due to air resistance 10lb must have had fallen first..

    please reason the correct answer
     
  2. jcsd
  3. Oct 21, 2015 #2

    Borg

    User Avatar
    Gold Member

    The difference in air resistance between the two spheres is neglible.
     
  4. Oct 21, 2015 #3

    faiziqb12

    User Avatar
    Gold Member

    but accordi
    but force of friction must vary with diffrent mass
    won't it
     
  5. Oct 21, 2015 #4

    Borg

    User Avatar
    Gold Member

    Air resistance is dependant on surface area. Again, the difference is going to be negilible.
     
  6. Oct 21, 2015 #5

    faiziqb12

    User Avatar
    Gold Member

    then can you please answer why a sheet of paper and a lead sheet of the same surface area experience different air resistance forces

    please reply ASAP
     
  7. Oct 21, 2015 #6

    gneill

    User Avatar

    Staff: Mentor

    We won't do your work for you. You need to make some investigative effort here.

    Choose representative masses for two objects. Assume that air resistance is identical for each, maybe call it fair. Draw Free Body Diagrams for both. Determine expressions for the accelerations. How do the accelerations compare?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: NSO class 9th
  1. 9th Homework doubts! (Replies: 8)

  2. Standard 9th (Replies: 5)

Loading...