Is it compulsory that non-contact forces are having both the properties, i.e., attraction and repulsion?

Write the force with which the earth attracts the objects towards it.

Explain, how pressure can be defined along with some suitable examples.

A sharp axe cuts the log earlier than a blunt axe. Explain why.

Pressure exerted by liquid depends on what factor?

Name the device used to measure atmospheric pressure.

Give the numerical value of atmospheric pressure at sea level.

As we go to high altitude the atmospheric pressure goes on decreasing. Give the reason.