changes in earth and sky

Introduction - We have learnt that a force changes or tends to change the state of rest, speed or direction of motion of an object, i.e., the force produces an acceleration. In this chapter, we are going to identify one of the forces which produces acceleration in all objects on..

Meteors are popularly known as "falling stars" or "shooting stars". They are often seen as a streak of light flashing across the night sky. They are really not stars. A meteor is caused by a grain of dust from space. As it enters the blanket of gases that surround the earth, the..

Around (600 - 500 B.C) the 'Samkhya' philosophy was popular. It asserted that matter was made up of five 'bhutas' or elements consisting of akasa (sky or space), vayu (air), tejas (fire), ap (water) and kshiti (the Earth). These bhutas, besides sharing common properties like co..

It is called the red planet. The rocks on Mars are full of rusted iron. This is why the planet looks red. Huge storms of dust can also make the sky look pink. Mars has two very odd little moons called Deimos and Phobos. They look like giant potatoes and are pitted with craters. The space ..

Universe - Universe consists of all matter and all light and other forms of radiation and energy. It consists of everything that exists anywhere in space and time. The universe includes the earth, everything on the earth and within it and everything in the solar system. All star..

Introduction - Oscillatory motion, or periodic motion, is the most common type of motion. Heartbeat of animals, the seasons of the year, the swinging of the pendulum of a clock and the vibrations of atoms in solids are periodic in nature. Two types of motion that are closely associated with oscilla..

Introduction - Let us began this chapter with the following statement: Often a physician may want to test how small changes in dosage can affect the body's response to a particular drug. An economist may want to study how investment changes with variation in interest rates. How ..

The Doppler effect provides a convenient means of tracking a satellite that is emitting a radio signal of constant frequency. The frequency of the signal received on the Earth changes as the satellite is passin..

Drop a stone from a height. What do you observe? The stone which was initially at rest starts moving towards the ground and attains a maximum speed just before it touches the ground. The stone is not moving with uniform speed. Its speed keeps changing at every instant, which means that th..

One morning, the Nawab call a) called his minister and said him b) told that I wanted the length and c) he breadth from the earth d) of measured. He also feel the e) felt need to have the stars on the f) in sky counted. The minister says g) said or re..