85.5 applications of Newton's law Exercise 4: There are three lulu blocks of mass m1, m2, m3 respectively, and m>m,+m Pulleys and strings are B massless. the kinetic friction forces between the pulley and the strings are ignored.(a) mr m m3 find the accelerations of mly? m, and ma.()what are the tensions of the two strings 85.5 applications of Newtons law Solution T3 (a) The free-bod n diagrams mm a1 at a, mg a2Im,g 38 1-T1=m1a1 m2+m2an1-72=m22 m3+m3a1-T=-m3a3 T=T+TT=T T219 A B m1 m2 m3 §5.5 applications of Newton’s law Exercise 4: There are three blocks of mass m1, m2, m3 respectively, and m1>m2+m3 . Pulleys and strings are massless, the kinetic friction forces between the pulley and the strings are ignored. (a) find the accelerations of m1, m2 and m3. (b) what are the tensions of the two strings. 2 3 a′ = a′ T1 = T2 +T3 T2 = T3 1 1 1 1 m g −T = m a m3 g m3a1 T3 m3a3 + − = − ′ m2 g m2a1 T2 m2a2 + − = ′ B T1 r T2 r a1 r T3 r m1 m g r 1 T1 r 1 a r m3 m g r 3 T3 r 3 1 m a r 3 a′ r + m2 m g r 2 T2 r m2a1 r 2 a′ r §5.5 applications of Newton’s law Solution: (a) The free-body diagrams