Final answer:
The problem defines tasks associated with calculating force and pressure in a hydraulic system of a backhoe, involving principles of physics and engineering, specifically concerning forces, pressures, and mechanical advantages.
Step-by-step explanation:
The given problem relates to a hydraulic system of a backhoe, which lifts a certain load using hydraulic principles. The task involves (a) calculating the force the secondary cylinder must exert to support a load and a brace with a shovel, (b) determining the pressure in the hydraulic fluid, and (c) computing the force a person must exert on a lever, to create the necessary pressure.
To solve part (a), we need to calculate the total weight the secondary cylinder is lifting and convert it into force (F), remembering to account for the gravitational acceleration (9.8 m/s2). For part (b), we'll use the formula for hydraulic pressure (P = F/A), where A is the area of the cylinder's cross-section. Finally, for part (c), we employ the principle of conservation of energy and the mechanical advantage concept to find out the force needed on the lever.
Important note: Figures mentioned such as 11.42 and 11.48 are presumed to be illustrations that depict the hydraulic system in use.