Final answer:
To determine the current density, use the formula J = I / A, where J is the current density, I is the current, and A is the cross-sectional area. For a current of 0.87 A and an area of 5.26 mm², calculate J by converting the area to square meters and dividing the current by that area.
Step-by-step explanation:
The question is about calculating the current density, which is a concept in Physics specifically related to the flow of electric current through a conductor. To find the current density (J), which is a vector quantity, we use the formula J = I / A, where I is the current in amperes, and A is the cross-sectional area in square meters. Given the current I = 0.87 A and a cross-sectional area A = 5.26 mm² (which is equal to 5.26 x 10^-6 m²), the current density can be calculated.
Using these values, the current density J is computed as follows:
J = I / A = 0.87 A / (5.26 x 10^-6 m²).
Your task involves performing this calculation. This concept is crucial to understanding how electric fields and resistivity affect current flow through materials, as described in Ohm's Law and the study of resistivity and resistance.