Unformatted text preview: Physics 0174 Recitation Week 11: Review 1.) A mass is set to slide along a frictionless track with a loop‐the‐loop of radius R. What is the minimum h that will allow the mass to make it around the loop without falling off? Assume the mass starts from rest. 2.) A 4.5 kg dog stands on an 18 kg flatboat at a distance 6.1 m from the shore. It walks 2.4 m relative to the boat toward shore and then stops. Assuming no friction between the boat and the water, how far is the dog from the shore? 3.) A billiard ball moving at 5.00 m/s strikes a stationary ball of the same mass. After the collision, the first ball moves at 4.33 m/s, at an angle of 30.0o with respect to the original line of motion. Assuming an elastic collision (and ignoring friction and rotational motion), find the struck ball’s velocity. 4.) There are 4 pulleys connected by 2 belts. Pulley A (radius 15 cm) drives the system by rotating at 10 rad/s. Belt 1 connects pulley A and pulley B (radius 10 cm) which is attached rigidly (and concentric) to pulley B’ (radius 5 cm). Belt 2 connects pulley B’ to pulley C (radius 25 cm). What is the angular speed of pulley C? How could the setup be changed to make C rotate faster? Are there multiple options? 5.) Consider the free body diagrams for the 2 wheels of a bicycle accelerating from rest. Assuming static friction keeps the tires from slipping at all, draw the friction acting on the wheels and their accelerations. Note the rear wheel is imparted an angular acceleration from pedaling, while the front wheel is just pushed forward at its axle. 6.) A uniform ladder whose length is 5.0 m and whose weight is 400 N leans against a frictionless vertical wall. The coefficient of static friction between the foot of the ladder and the ground is 0.46. What is the greatest distance the foot of the ladder can be placed from the base of the wall without the ladder slipping? ...
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This note was uploaded on 04/06/2009 for the course PHYS 0174 taught by Professor Kohler during the Spring '08 term at Pittsburgh.
 Spring '08
 KOHLER
 Friction, Mass

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