What type of valve in an aircraft hydraulic system permits fluid to flow freely in one direction, but restricts the rate at which fluid is allowed to flow in the other direction

Check valve

Explanation:

Check valve is used in the hydraulic system of an aircraft which permits the flow of fluid only in one direction and restricts the flow of fluid in the other direction.

The check valve may or may not be the integral part of the hydraulic system. A typical check valve consists of a spring loaded ball and seating groove inside the housing case of the valve. The spring gets compressed in one direction only according to its design and hence is a one way flow valve.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards