Question

A)

A block of mass M is pulled over a rough horizontal surface. The block has a coefficient of kinetic friction with the surface of u. The block is subject to the normal force, the friction force, the force of gravity, and a force from a rope of magnitude T which pulls up and to the right at an angle of 0 with the horizontal. The box was initially travelling to the right at speed v = 1.4". If M =8.5kg, u=0.12, T =42N, and 0=37.5 degrees, what is the block's kinetic energy after it has been displaced a distance d=5.0m to the right? Answer in Joules. Answer: 8.33 x The correct answer is: 140.29 Try another question like this one

b) using the information from the previous question what is the net work done on the block as it is displaced?

Answer 1

given as shown in fig. Data = Jux=0.12 ↑ Tsino T=420 IM= 8.5kg 33.po fa MAN dasm mg N = mg - Tsino = 8.5*9.81 42 x sin 37.5 = 57.817 N fa MKN = 0.12 x 57.817 = 6.938 N now fuet = ma T (os 37'5 - 6.938=8.5xa a= 3.1038 ulsee?

initial (u)= 14 w fiec now by ear of motion as : ² u²t gas 8² 14² + 2x 3.1038x5 To= 5.744 mlece & KE = mo? 2 1 / 3 x 8.5x5.7462 ( KE 2 140.24 Julen