Final answer:
The stress in a 10" x 10" rectangular prism with a 20,000 lb load is calculated by dividing the load by the cross-sectional area, resulting in a stress of 200 lbf/in².
Step-by-step explanation:
To calculate the stress in the prism, we start by using the formula for stress:
stress (f) = load (P) / cross-sectional Area (A)
Given a load (P) of 20,000 lb placed on top of a 10" x 10" rectangular prism, we first convert the area to square inches (since 1 inch = 2.54 cm):
- Area (A) = 10 in x 10 in = 100 in².
- Then we convert the load from pounds to pounds-force (lbf), noting that in the Imperial system, lb is a unit of mass. For this calculation, we assume that lb and lbf are equivalent in the context given (as is common in engineering practice in the Imperial system), so P = 20,000 lbf.
- Now, we apply the formula to find the stress:
- Stress (f) = 20,000 lbf / 100 in² = 200 lbf/in².
The stress in the prism is therefore 200 lbf/in².