Pulling out a book (friction problem)

  • Thread starter Thread starter center o bass
  • Start date Start date
  • Tags Tags
    Book
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 2K views
center o bass
Messages
545
Reaction score
2
Two books are lying on top of each other on a table. The upper book has a mass m1 , and
the lower book has a mass m2 . The coefficient of static fric-
tion between the books is µ1 . The coefficient of static friction
between the book and the table is µ2 and the coefficient of
dynamic friction between the book and the table is µd . You
pull on the lower book with a horizontal force F .

(a) How large must F be for you to start pulling both books
along the table.

(b) How large must F be for you to pull out only the lower
book? (a) I reasoned that to get the books going at all we must have that [tex]F> \mu_s(m_1+m_2)g[/tex] and then once it is going we must ensure that [tex]\mu_1 m_1g > F > \mu_d(m_1+m_2)g[/tex]

(b) To get the book going we must again have that [tex]F> \mu_s(m_1+m_2)g[/tex], but then once it is going [tex]F > \mu_d(m_1+m_2)g \wedge \mu_1 m_1g[/tex].

Is this the correct reasoning here? We must split the problem up in two parts right?
 
Physics news on Phys.org
Noone who can help me with this?
 
You seem to have a lot of extra stuff in your response. Part a asks for the value of F required to move the books. Please provide one answer only for the value of F in part a and correct any typos.

For part b, again provide one answer and correct any typos. Whats that ^ in your equation??