The intrinsic permeability () of silty sand is 5 × 10-11 m2; the porosity of this media is 0.04. Groundwater (20℃) is flowing through this media from Point 1 (piezometric head = 12 m) to Point 2 (piezometric head = 5 m) over a distance of 1260 m. Assuming the hydraulic gradient in between is constant, how much time (in days) will it take for the groundwater to arrive at Point 2 from Point 1?

Afour cylinder four-stroke in-line engine has a stroke of 160mm, connecting rod length of 150mm, a reciprocating mass of 3kg and its firing order is 1-3-4-2. the spacing between cylinders is 100mm. i. show that the engine is in balance with regard to the primary inertia forces and primary 3. a and secondary inertia couples. li determine the out of balance secondary inertia force ii. propose ways of balancing this out of balance force and discuss the challenges that will arise