What is the proper stance to use when lifting

1.) Keep a wide base of support.

2.) Squat down, bending at your hips and knees only.

3.) Keep a good posture, before, and, during lifting.

4.) Slowly lift by straightening your hips and knees, do NOT use your back.

5.) Hold the load as close to your body as possible, roughly at your belly button.

6.) Use your feet to change direction, taking small steps.

7.) Lead with your hips when/if you need to change direction.

8.) Set down your load carefully, squatting with the knees and hips only.

I've attached an image of proper posture as well. Hope this helps :)

Gravity, acceleration or by force outside a closed container and by hydraulic mechanism and velocity of fluid.

Explanation:

Fluid pressure is defined as the force which is acted on unit area on an object which is present in the fluid or on the closed container's surface. This pressure can be changed by the acceleration, gravity, or forces  which are present outside a closed container.

Since there is no any definite shape of a fluid, the pressure which applies in these fluids observe in all directions. Fluid pressure can also be increased  by the  hydraulic mechanisms and velocity change of the fluid.