Generics - General Questions

Why can't you write new T() inside a generic class?

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        java.util.List<Integer> nums = java.util.List.of(1, 2, 3);
        int s = 0;
        for (int n : nums) s += n;
        System.out.println(s);
    }
}

What is the output of the following program?

class Main {
    static <T extends Comparable<T>> T max(T a, T b) { return a.compareTo(b) >= 0 ? a : b; }
    public static void main(String[] args) { System.out.println(max(3, 9) + " " + max("pear", "apple")); }
}

A raw type is:

What is type erasure?