Answer:
Option A is correct.
Inheritance, superclass, subclass
A new class of objects can be created conveniently by **inheritance**; the new class (called the **superclass**) starts with the characteristics of an existing class (called the **subclass**), possibly customizing them and adding unique characteristics of its own.
Explanation:
A class is a term in object oriented programming that is extensible program code used to create, name and implement what you want the objects to do.
Inheritance is used to describe the making of new classes from already existing classes. The general properties of the old classes remain in the new classes created from them.
Hence, the new classes (because they're usually an improvement on the old classes as they hold on to the wanted properties of the old classes and additional great ones are added or modified) are called superclasses and the old, already existing ones are called subclasses.
Answer:

Explanation:
Four people standing on the ground each of mass and usually this questions have to find the final angular velocity

The radius 
Angular velocity 
The moment of inertia total is 
Momento if inertia


Angular momentum

Solve to w2



The amount of energy used in the billing period is 5,400,000,000 joules.
One kWH is the amount of energy transferred in one hour, there 1 kWh is equal to
1 kWh=1*1000*(J/s)*3600 s
=3600000 J
Thus the amount of energy in joules consumed by the user for the billing period is =1500*3600000=5,400,000,000 J.
The amount of energy used in the billing period is 5,400,000,000 joules.
Answer: Magnes
Explanation: Magnes found that the nails and buckle of his sandals and the tip of his staff were attracted to the rock he was standing on. He dug up the Earth to find lodestones. Lodestones contain magnetite, a natural magnetic material Fe3O4.