Chapter 8, Problem 7P

4. The mine car and its contents have a total mass of 6000 kg and a centre of gravity at G. If the coefficient of static friction 10 kN between the wheels and the 0.9 m •G tracks is u = 0.4 when the wheels are locked, find the normal force acting on the front wheels at B and the rear 0.15 m 0.6 m - 1.5 m wheels at A when the brakes at both A and B are locked. Does the car move? [Ans. NA = 16.5 kN, Ng =42.3 kN, the car does not move] %3D lyp

PLLLSS ANSWER WITHIN AN HOUR    The spool in the given figure weighs 25 N, and its center of gravity is located at the geometric center. The weight of block C is 50 N. The coefficients of static friction at the two points of contact are as shown. Determine the largest horizontal force P that can be applied without disturbing the equilibrium of the system.

1. The two 890 N blocks are pushed apart by the 150 wedge of negligible weight. The angle of static friction is 12° at all surfaces. Determine the force P required to start the blocks moving. 890N 890N