Final answer:
Electromagnetic induction and radar can be used to detect big and solid amounts of steel on the ground at long distances, although radar may not be able to differentiate between metal and non-metal objects. Factors such as soil composition and environmental conditions can affect the accuracy of these methods.
Step-by-step explanation:
Physics
Electromagnetic induction is a technique that can be used to detect metals, even at long distances. It works by generating an electromagnetic field and detecting any changes in the field caused by the presence of metal objects. This method is commonly used in landmine detection, geophysical prospecting, and at airports for security screening.
Radar is another effective method for detecting large and solid amounts of steel on the ground. Radar systems use microwaves to detect and time the echoes produced when the microwaves bounce off objects. While radar may not be able to differentiate between metal and non-metal objects, it can still accurately detect and locate the presence of large steel structures, such as vehicles, at long distances.
By combining the techniques of electromagnetic induction and radar, the detection of big and solid amounts of steel on the ground at long distances becomes practically possible. However, it is important to note that the accuracy and effectiveness of these methods can be influenced by factors such as soil composition and environmental conditions.