Final answer:
To calculate the required diameter of a steel rod so that it does not stretch more than 1.0 cm when a 2.5 × 10^4-kg truck passes by it, we can use the formula for stress.
Step-by-step explanation:
A cylindrical rod is usually about 12 inches (30.5 cm) long with a uniform diameter along its entire length. To calculate the required diameter of a steel rod so that it does not stretch more than 1.0 cm when a 2.5 × 10^4-kg truck passes by it, we can use the formula for stress. The stress on the rod can be calculated using the equation: stress = force/area.
Since the rod supports all the weight of the truck, the force acting on it is equal to the weight of the truck (mass × acceleration due to gravity). By rearranging the formula, we can find the required area of the rod, which is directly related to its diameter.
Once we plug in the values for the mass of the truck and the maximum stretch, we can solve for the diameter of the rod to ensure it does not stretch more than 1.0 cm.