Practice Final

1. A coin lies on a wooden plank a distance 2 m from its right edge. The plank is slowly raised with the coin remaining stationary. When the coin is 1.2 m above the ground, it begins to slide along the plank. What is the value of the coefficient of static friction between the plank and the coin? a)0.80 b)0.75 c)0.60 d)0.40 e)0.25 2. (P) The diagrams below show identical masses held by strings under tension. The pulleys are frictionless and the same type of string is used in each case. Consider the longest string segment in case 2. Rank the cases according to the wave speed in the string, largest to smallest? a)1, 3, 2 b)3, 2, 1 c)2, 1, 3 d)1=3 (tie), 2 e)1, 2=3 (tie) 3. A damped harmonic oscillator consists of a block of mass 2.5 kg attached to a spring with spring constant 10 N/m to which is applied a damping force (in Newtons) of the form F= -0.1v, with v the velocity in m/s. The spring is stretched a distance x m and released. After four complete oscillations, what fraction of the mechanical energy is retained by the system? a)0.99 b)0.90 c)0.77 d)0.60 e)0.48 4. Chocolate milk is pumped through a vertical section of pipe shown below. Compared to the lower level (location 1), the milk flow at the upper level (2) a)has greater speed and lower pressure. b)has greater speed and greater pressure. c)has lower speed and lower pressure. d)has lower speed and greater pressure. e)has the same speed and lower pressure. 5. (P) Which of the following items cannot be associated with simple harmonic motion? a)The amplitude of motion is small. b)The acceleration varies with time in a sinusoidal manner. c)The mechanical energy of the system is not constant. d)The direction of the force is opposite that of the displacement. e)The magnitude of the force increases as the square of the displacement. 6. In the left figure below (case i), mass m makes small oscillations on a spring with period T. In the right figure (case ii), the spring has been cut in half and the same mass is then attached. What is the period of small oscillations for the system in case (ii)? (Hint: Consider the long spring to be two short springs in series.) a) 2T b) ?2 T c) T / 2 d) T / ?2 e) T 7. (P) Mr. Snowy, the snow figure shown below, slides down a frictionless incline angled ? degrees (0