Physics Questions

The atmospheric pressure at the surface of the Earth is due to gravitational pull of the earth and is about 14.7 psi.

That means that the weight of a column of air which has a cross section of 1 square inch and which stretches from the surface of the Earth to space is 14.7 pounds. 

Flows out of Newton's first law of motion.

Aluminium being a good conductor of heat conducts away the heat from the substance quite easily and causes quick freezing.

The power source such as a Battery of an IED creates an electrical charge.

What are IED's ::

An Improvised Explosive Device (IED) is a bomb constructed and deployed in ways other than in conventional military action. It may be constructed of conventional military explosives, such as an artillery shell, attached to a detonating mechanism. IEDs are commonly used as roadside bombs.

In this position, the head light will be at the principal focus so that the rays of light falling on the cancave mirror will be rendered parallel

A Sound wave needs a medium for propogation. Hence, Sound cannot travel through a vacuum.

A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.