【单选题】Consider an object on a rotating disk a distancerfrom its center, held in place on the disk by static friction. Which of the following statements isnottrue concerning this object?
A.
If the angular speed is constant, the object must have constant tangential speed.
B.
If the angular speed is constant, the object is not accelerated.
C.
The object has a tangential acceleration only if the disk has an angular acceleration.
D.
If the disk has an angular acceleration, the object has both a centripetal acceleration and a tangential acceleration.
【单选题】Analyze the following code: public class Test1 { public Object max(Object o1, Object o2) { if ((Comparable)o1.compareTo(o2) >= 0) { return o1; } else { return o2; } } }
A.
The program has a syntax error because Test1 does not have a main method.
B.
The program has a syntax error because o1 is an Object instance and it does not have the compareTo method.
C.
The program has a syntax error because you cannot cast an Object instance o1 into Comparable.
D.
The program would compile if ((Comparable)o1.compareTo(o2) >= 0) is replaced by (((Comparable)o1).compareTo(o2) >= 0).