A flat (unbanked) curve on a highway has a radius of 170.0 m. A car rounds the curve at a speed of 25.0 m>s. (a) What is the minimum coefficient of static friction that will prevent sliding? (b) Suppose that the highway is icy and the coefficient of static friction between the tires and pavement is only one-third of what you found in part (a). What should be the maximum speed of the car so that it can round the curve safely?
PHYS 242 BLOCK 4 NOTES Sections 27.1 to 27.7, 27.9 Consider a freely-pivoted compass needle(or a bar magnet) in the earth’s magnetic field. The magnetized object’s north pole (N-pole) points geographically north and itssouth pole (S-pole) points geographicallysouth (neither exactly so). Consideringthe earth as a magnet,currently its south magneticpole is located near its north geographic pole and vice versa (see Fig.27.3). F = q E defines the electricfield E and F = qυ × B defines the magnetic field B . This vector 0 0 equation tells us that anynon-zeroF is perpendicular toboth υ and B . Also, F is in the same direction as υ → → → × B for positive charge and oppositeυ × B fo
