1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Finding normal force

  1. Aug 27, 2015 #1

    Please help with below. is it correct?

    A 41 kg crate rests on a horizontal floor and a 67kg person is standing on the crate.

    a. determine the magnitude of the normal force the floor exerts on the crate

    b. determine the magnitude of the normal force that the crate exerts on the person

    2. Relevant equations


    3. The attempt at a solution

    a. 1080
    b. 670
  2. jcsd
  3. Aug 27, 2015 #2
    Try drawing a force diagram for both the person on the crate and the crate and try summing your forces for each individually. The answers should become clear!

    Also, this belongs in introductory physics.
  4. Sep 1, 2015 #3
    AlephNumbers, this was an impertinent response.

    Pizza Dave, you calculated this answer correctly, but it looks like you substituted 10 for the force of gravity instead of the actual value of 9.8. This may help your answers be more accurate in the future!
  5. Sep 2, 2015 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You should always specify units (unless instructed otherwise).
    Both values are just approximations. Often students are told to use 10 ms-2. On the other hand, if it is approximated to 10 then, logically, the answers should only be given to the same precision, e.g. 1100 N for (a).
    And you mean gravitational acceleration, not force.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted