Chapter 13, Problem 7P

The 20-kg crate is subjected to a force having a constant direction and a magnitude F = 100 N. When s the crate is moving to the right with a speed of 8 m/s. Determine its speed when s = 25 m. The coefficient of kinetic friction between the crate and the ground is 15 m, %3D µ= 0.25 30°

Determine the speed v which the 605-kg four-man bobsled must have in order to negotiate the turn without reliance on friction. Also find the net normal force N exerted on the bobsled by the track. 40 -p = 50 m %3D Answers: V = i m/s N = kN

2. The car, having a mass of 1000 kg, is traveling horizontally along a 20° banked track which is circular and has a radius of curvature of p = 100 m. If the coefficient of static friction between the tires and the road is us = 0.3, determine the minimum and maximum constant speed at which the car can travel without sliding down and up the slope. Neglect the size of the car. e= 20°

The 35-kg crate is subjected to a force inclined to 70° respect to vertical plane having a constant direction and a magnitude F = 150 N. When s = 20 m, the crate is moving to the right with a speed of 10 m/s. Calculate for normal reaction and its speed when s = 30 m. The coefficient of kinetic friction between the crate and the ground is mk = 0.35.

When s = 55 cm, the spring is unstretched and the 9-kg block has a speed of 6.19 m/s down the smooth plane. If the coefficient of kinetic friction between the surface and the block is 0.25, find the distance (mm) s at which the block stops. k = 208 N/m 6.19 m/s F = 118 N 30

The 56.28 kg crate is hoisted up the 0 = 27° incline by the pulley system and motor M. If the crate starts from rest and, by constant acceleration, attains a speed of 8.17 m/s after traveling 7.84 m along the plane, determine the supplied power to the motor if the crate has moved 8 m and the coefficient of kinetic friction between the plane and the crate is Hk = 0.3. Neglect friction along the plane. The motor has an efficiency of 0.691. M

If blocks A and B of mass 10 kg and 6 kg respectively,  are placed on the inclined plane and released, determine  the force developed in the link. The coefficients of kinetic  friction between the blocks and the inclined plane are  mA = 0.1 and mB = 0.3. Neglect the mass of the link.

The 1.9-kg slider is released from rest in position A and slides without friction along the vertical-plane guide. Determine the normal force exerted by the guide on the slider (a) just before it passes point C, (b) just after it passes point C, and (c) just before it passes point E. The normal forces are positive if they point up and/or to the left, negative if they point down and/or to the right.

The 110-lb boy at A is suspended from the cable that passes over the quarter circular cliff rock. What horizontal force must the woman at A exert on the cable in order to let the boy descend at constant velocity? The coefficients of static and kinetic friction between the cable and the rock are μs=0.4 and μk=0.35, respectively.