A cable is placed around three parallel pipes. Two of the pipes are fixed and do not rotate; the third pipe is slowly rotated. Knowing that the coefficients of friction are 0.25 s = and 0.20, k = determine the largest weight W that can be raised (a) if only pipe A is rotated counterclockwise, (b) if only pipe C is rotated clockwise.

PY 205 Week 3 Notes Chapter 4 and 5 Newton’s Laws 1. Velocities don’t change unless a net force acts upon it (qualitative) 2. The acceleration of a body is directly proportional to the net force acted on it (quantitative) a. Fnet = (mass)(acceleration) 3. Forces occur between two objects – if A exerts a force on B then B exerts a negative force on A. a. Fnet = Fxi +Fyj + Fzk b. The sum of all the forces on x = ma(x) c. The sum of all the force on y = ma(y) Applications of Newton’s laws - Kinetic motion - sliding friction - The force acts opposite to the direction of the object’s velocity - Normal force = shows that the friction force is approximately proportional to the normal force – the