Question

Save Answer QUESTION 10 points The given figure shows two blocks A and B of masses 200 and 300kg respectively. The blocks are joined by an inextensible cable. As the system was on rest; a force F-5430 N directed horizontally to the left is applied on block A Use the work and energy principles to determine the velocity of block A after it has moved 0.4m. Assume that the coefficient of kinetic friction between block A and the plane is 0.25 and that the pulley is weightless and frictionless. Afterward fill in the given blanks by the appropriate answers (if the answer is real number; it must be typed in the form having two decimal digits, no fractions are accepted: ie. 0.25 is accepted rather than 1/4) А. B

Answer 1

Ginen: masses of A and B Blocks; MA D 200 kg f MB = 3ookg Tamara Mag F = 5430N Coefficient of kinetic friction: B Mk= 0.25 meg intially system was rest: so initial velocity of block A is zero : Uro so initial Kinetic Energy of system is Zero iie. KE initial 0 now by force the block A with acceleration 9 move to the left now from free body diagzam of block A: MAG F - Fic-T where fx = lkn and N= normal force - MAG o MAQ= F - MKMAG-T now from free body diagsam of mB9 T-M MBg block Bi

TT 2 (MAX MB) u2 2 f-g(MK Math (MAIMB) 19 MB] (matma). (0.4) תוך v2 = 엌 V= [f-golema tms)] (0.4)*2 (matme) [f-g("kMatma)] (0.8) (Matme) [5430 – 9.81 (0.25% 200 +300)) x(0.8) (200+300) M & v= 3. 1944 UL Ve 1.787 els VE 1079 m/s Required velocity of block A Dow " by force (f=5430N) block A move to the left so The tendency of motion of the system at released from rest, the effect of F, that B under moves up Now Diction force between the plane and block Ai fr = lkn IKMA & fic 0.25 x 200 x 9.81 fk = 490.5 Required fiction force

The kinectic energy befor system motion : of the Kinetic Energy = (atme) ? I (2007 300) (0)2 2 Kinective energy kinectic o foule required energy The velocity of block A after ou of motion : V- 1.79 m/s directed to left The kinectic energy of the system aften 0.4 motion : Kinectic energy = I matme) v2 ( 2001 300) (1.7872 td Kinectic energy = 798-6 foule or Kinectic energy = Loule 799.0 Required Eneggy