PHYS 114 Midterm: 114 Exam 2 MC solutions
26 views4 pages
Document Summary
[50 points total] multiple choice questions, 5 points each. Use the following setup for questions 1 through 3: a block of mass 4 kg slides horizontally across rough ground. The block is initially moving at 3 m/s, and friction brings the block to rest after 2 m: consider system b (consisting of the block) and system bg (consisting of the block and the ground). In both systems, the kinetic energy is decreasing since the block is slowing down, and the potential energy is not changing. Thus in both systems the mechanical energy decreases: what is the coefficient of kinetic friction between the block and the ground, 0. 06, 0. 08, 0. 15, 0. 23, 0. 46. The work done by friction is equal to the change in kinetic energy. = 0. 23: suppose you exerted a force on the block to keep it moving with its initial speed. What is your power output: 6. 8 w, 9 w, 27 w, 29 w, 120 w.