center o bass
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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 F> \mu_s(m_1+m_2)g and then once it is going we must ensure that \mu_1 m_1g > F > \mu_d(m_1+m_2)g
(b) To get the book going we must again have that F> \mu_s(m_1+m_2)g, but then once it is going F > \mu_d(m_1+m_2)g \wedge \mu_1 m_1g.
Is this the correct reasoning here? We must split the problem up in two parts right?
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 F> \mu_s(m_1+m_2)g and then once it is going we must ensure that \mu_1 m_1g > F > \mu_d(m_1+m_2)g
(b) To get the book going we must again have that F> \mu_s(m_1+m_2)g, but then once it is going F > \mu_d(m_1+m_2)g \wedge \mu_1 m_1g.
Is this the correct reasoning here? We must split the problem up in two parts right?