What is the difference between push and pull? 

Differentiate between buoyant force and frictional force.

Chintu's mother has a transferable job in the Indian Army. On receiving a transfer order, Chintu's mother packed the clothes, utensils, furniture, etc and dispatched these by a truck to another town where they have recently shifted. Chintu and his family travelled by train. On reaching the destination the truck was waiting for them. They started unloading the truck and putting things in the required rooms. Chintu tried hard to pull his bed into his room. But was able to move it very slowly. With the purpose of helping Chintu, his father came and started pulling the bed from the opposite end and the bed stopped moving at all. Both of them kept on pulling the bed for some time but could not move it. They were perplexed to see this happening. Chintu remembered reading about something similar in chapter Force and Pressure of his science book. Do children of the armed force personnel sacrifice anything for the defence of their country?

Jignesh and Sukhdeep were lying on the grass in the lawn and looking at the moon and the Stars in the open sky. They were discussing What they had learned in chapter 11 of their science textbook. 
Jignesh: Sukhdeep, did you know that there are more stars in the universe than there are grains Of sand On the Earth? 
Sukhdeep: wow! I never knew it, Did you know that the moon has no light of its own? It is shining because it's reflecting the light from the sun? 
Jignesh: Yes I know, and furthermore, there is no air on the moon. 
Sukhdeep: Does it mean that there will be no atmospheric pressure on the moon? 
Jignesh; No, it is not that. The atmospheric pressure on the moon depends on the gravity of the moon. So it will have an atmospheric pressure. 
Sukhdeep: Are you sure? I think that atmospheric pressure depends on the volume of air and as there is no air on the moon, so there is no pressure. 
Jignesh; Nope, I am very sure that there is atmospheric pressure on the moon. Furthermore, I have heard that a new moon day or amavas is a very unlucky day and we should not start any work on that day. 

Is Jignesh right? Give reasons. 

Jignesh and Sukhdeep were lying on the grass in the lawn and looking at the moon and the Stars in the open sky. They were discussing What they had learned in chapter 11of their science textbook. 
Jignesh: Sukhdeep, did you know that there are more stars in the universe than there are grains Of sand On the Earth? 
Sukhdeep: wow! I never knew it, Did you know that the moon has no light of its own? It is shining because it's reflecting the light from the sun? 
Jignesh: Yes I know, and furthermore, there is no air on the moon. 
Sukhdeep: Does it mean that there will be no atmospheric pressure on the moon? 
Jignesh; No, it is not that. The atmospheric pressure on the moon depends on the gravity of the moon. So it will have an atmospheric pressure. 
Sukhdeep: Are you sure? I think that atmospheric pressure depends on the volume of air and as there is no air on the moon, so there is no pressure. 
Jignesh; Nope, I am very sure that there is atmospheric pressure on the moon. Furthermore, I have heard that a new moon day or amavas is a very unlucky day, and we should not start any work on that day. 

Is starting a new work on a new moon day really unlucky? Give reasons.