How to Calculate Force & PSI
- 1). Measure the weight of the object, in pounds, using a scale. For example, you might have a 50-pound cement block.
- 2). Determine the length and width, in inches, of the bottom surface of the force-applying object. Be sure to measure the length and width of the side of the object that rests on another surface. Continuing the example, the length and width of the cement block might be 24 inches and 15 inches, respectively.
- 3). Multiply the length by the width to get the area in square inches. Performing this step, for the example, leads to 24 inches times 15 inches, or an area of 360 square inches.
- 4). Divide the weight by the area to obtain the pressure exerted by the object on the surface in psi. Now you have, for the example, 50 pounds divided by 360 square inches, or a pressure of 0.14 psi.
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