Physics Questions

Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun.

• Kepler’s three laws of planetary motion can be stated as follows:

(1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci.

(2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.

(3) The squares of the sidereal periods (of revolution) of the planets are directly proportional to the cubes of their mean distances from the Sun.

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.

The flow of thermal energy due to differences in their temperatures is called Heat.

Integrated circuit (IC) is a tiny device that controls electric signals in such electronic equipments as computers and T.V sets. Many integrated circuits contain thousands of electronic parts on a paper - thin chip of silicon. These parts include capacitors, diodes, all in a very small, compact space.

When a running car stops suddenly, the passengers tends to lean forward because of Inertia of motion.

General purpose gloves - utility gloves are recommended for cleaning procedures, such as handling soiled linens or decontaminating care areas. Utility gloves are more tear and puncture resistant than other gloves.

Infrared radiation

Thermoplastic materials is a type of plastic material that can be cooled and heated several times without any change in their chemistry or mechanical properties.

Examples of Thermoplastic ::

• polyethylene,
• polypropylene,
• polyvinyl chloride,
• polystyrene,
• polybenzimidazole,
• acrylic,
• nylon and
• teflon