Physics 8A Week 5 Section Worksheet 1 1) The contestant now pulls the block of ice with a rope over his shoulder at the same angle above the horizontal as shown below. The coefficient of friction of ice can be found in Table 6.1 [in the textbook, /, = 0.1, #x = 0.03]. Calculate the minimum force F he must exert to get the block moving. (b) What is its acceleration once it starts to move, if that force is maintained? [Source: University Physics Volume 1, Chapter 6, Problem 63] 2) Two blocks of mass m and mass M are stacked on top of each other and are at rest on a flat frictionless table. A string is attached to the bottom block and is pulling with a tension T. What is the smallest value of the coefficient of static friction between the top and bottom block so that they do not slip? [Source: Mike Yen] 3) Two blocks are connected by a massless rope as shown below. The mass of the block on the table is 4.0 kg and the hanging mass is 1.0 kg. The table and the pulley are frictionless. (a) Find the acceleration of the system. (b) Find the tension in the rope. (c) Find the speed with which the hanging mass hits the floor if it starts from rest and is initially located 1.0 m from the floor. [Source: University Physics Volume 1, Chapter 6, Problem 43] m2 4) A block of mass mi hangs from an ideal rope attached to a block of mass my that sits on a ramp of incline angle @. Friction is present between my and the ramp. a) Assume that initial neither block is moving. Draw a separate free body diagram for each mass. b) If the blocks are not moving, what is the magnitude and direction of the force of static friction on my? c) If the block are not moving, what is the smallest possible value for the coefficient of static friction, /, between the ramp and my? d) Now someone briefly pushes the second block so that it begins to slide down. After the person stops pushing, what is the direction and magnitude of the force of kinetic friction on my if #k = 1/18? e) What is the acceleration of block 1? [Source: Nick Aldana] Physics 8A Week 5 Section Worksheet 1