Chapter 14, Problem 12P

Subject: mechanical

The 10-kg block shown in the figure below rests on the smooth incline. If the spring is originally stretched 0.5 m, determine the velocity of the block when a horizontal force P = 400 N pushes it up the plane s = 2 m

Solve it correctly

The 1600 kg car has a velocity of v the driver sees an obstacle 175 m away, in front of the car. It takes 0.8 s for him to react and lock the brake 100 km/h when causing the car to skid. The coefficient of kinetic friction between the tires and the road is p = 0.25. Find the best correct statement(s) from the following for this situation: ,= 100 km/h Select one or more: Work done by the frictionis equal to 617.4 KW The working forces are ficion and the wejght. The car will stop just in front of the pbstacle without hittungui The car will hit the obstadle. The car skid for the distance of 157.34m,

The position vector of a particle is given by r = 11ti + 2.0t²j - 0.9(t3 - 5)k, where t is the time in seconds from the start of the motion and where r is expressed in meters. For the condition when t = 4 s, determine the power P developed by the force F = 36i - 21j - 46k N which acts on the particle. Answer: P = i kW

Two weights of 96 pounds and 64 pounds move horizontally on a surface smooth, each spring has k = k1 = k2 = 600. At t = 0 the springs are unstretched and the weight of 96 has a velocity of 600 ft/sec away from the wall and the other is in repose. Solve the system of equations for the given conditions, and explain how the equations of motion are obtained for each mass ('x(t)' and 'y(t)').

2. The block (A) has a mass of 10 kg and the coefficient of dynamic friction between the block and the ground is μ = 0.3. Block B has a mass of 15 kg and slides down a frictionless pole. If the blocks start from at x=0 calculate: a. The distance block A moves after block B has fallen 4 m b. The relationship between the speed of A and the speed of B c. The work done by friction on block A d. The velocity of block B. B 2m A

The force F= 40s , acting in a constant direction on a 50-kg block, has a magnitude which varies with the position s of the block. Determine how far the block must slide before its velocity becomes 15m/s. When s=0, the block is moving to the right at v=10 m/s. The coefficient of kinetic friction between the block and the surface is µ, =0.32. 2.

plot. Note that the force is zero for all the times greater than 3s. The initially stationary 20 kg block is subjected to the time-varying horizontal force whose magnitude P is shown in the Draw Momentum-Impulse diagram showing the impulses of all effective forces and corresponding momentums. 2. Determine the time the block overcomes the friction and starts to slide on the surface. 3. Determine the time t, at which the block comes to rest. 14-0.40) R-0.60 ル my 20g P.N 150 3 1.8