Q7. The uniform 6.2-kg slender bar with a length of 2.7 m is pinned at point O. It is initially at rest, and then is subjected to a horizontal impulsive force at B. The average value of the force is 1,300 N, and its duration is 0.04 s. If the force causes the bar to swing to the horizontal position before falling, what is the distance h? Assume the bar is still vertical immediately after the impact. Your answer must include 2 places after the decimal point, and proper SI unit. Take g = 9.81 m/s2.

The 28-lb collar A is released from rest in the position shown and slides with negligible friction up the fixed rod inclined 28° from the horizontal under the action of a constant force P = 52 lb applied to the cable. Calculate the required stiffness k of the spring so that its maximum deflection equals 6 in. The position of the small pulley at B is fixed. P B 28" 28° 6" Answer: k = i 35" lb/ft k

3. Blocks AA and BB of mass 10 kg and 4 kg respectively, are placed on the inclined plane and released. The coefficients of kinetic friction between the blocks and the inclined plane are μAμAmuA = 0.1 and μBμBmuB = 0.5. Neglect the mass of the link

- Determine the acceleration of the system. - Determine the magnitude of the force that each crate exerts on the other.