Questions

When a program forks and the child finishes before the parent, the kernel still keeps some of its information about the child in case the parent might need it – for example, the parent may need to check the child’s exit status. To be able to get this information, the parent calls `wait()’; In the interval between the child terminating and the parent calling `wait()’, the child is said to be a `zombie’ (If you do `ps’, the child will have a `Z’ in its status field to indicate this.)

Shobha Rajadhyaksha, also known as Shobhaa De (born 7 January 1948), is the author of the book "Superstar India: From Incredible to unstoppable ". She is an Indian columnist and novelist. De is best known for her depiction of socialites and sex in her works of fiction, for which she has come to be known as the "Jackie Collins of India".

A Contact force is a force applied to a body by another body that is in contact with it. Contact force acts on a point of direct contact between the two objects. This force can either be continuous as a continuous force or can be momentary in the form of an impulse. Contact force is governed by Newton’s Laws.

Examples :: Contact force is responsible for most of the interactions we experience in the daily life.

1. Writing your name with a pen, pushing a car up a hill, lifting an object, etc...

2. Kicking a ball, hammering a nail, etc...

are some of the everyday examples where contact forces are at work.

In the first case, the force is continuously applied by the person on the car or pen or an object while in the second case the force is delivered in a short impulse.

Contact forces are often decomposed into orthogonal components

one perpendicular to the surface in contact called the normal force, and

one parallel to the surface in contact, called the friction force.