Physics

Why cooking at the top of hill is difficult? At higher altitudes, like hills, cooking food is difficult. Higher altitudes mean lower atmospheric pressure. The boiling point decreases if the pressure is low. So, at the top of the hill cooking takes a long time because due to lower pressure water starts to boil at … Read more

We know, velocity is a vector. It has both value and direction. So, change in direction or value will result in change of vector. So, if direction of an object going at uniform velocity changes, velocity will also change. Meaning, uniform speed does not always mean uniform velocity.

Specific heat is the quantity of heat required to raise the temperature of 1gm of a substance by 1 degree. The human body is composed of water, protein fat, and minerals. Its specific heat reflects this composition. With 75% water and 25% protein, the specific heat of the body would be Specific heat = 0.75 … Read more

Ultraviolet light produces reactions in the skin then visible light. Some of these reactions are beneficial and some are harmful. One of the major beneficial effects of UV light from the sun is the conversion of molecular products in the skin into vitamin D. Ultraviolet light from the sun affects the melanin in the skin … Read more

The walls of the heart consist of layers of muscle, wound several times around the atria and the ventricles in a complicated arrangement. The layers of muscle around the ventricles are thicker than those around the atria. The heart muscle pumps blood by its cyclic contractions and relaxation. The contracted phase of the heart is … Read more

Each of the pumps in the heart has two chambers. The upper chamber is called the atrium, and the lower chambers the ventricle (“belly”). The atria accumulate the blood arriving at the heart and then inject it into the ventricles. The ventricles eject the blood from the heart into the arteries; they perform most of … Read more

An open-tube manometer is a device for the measurement of the the pressure of a fluid, such as that contained in the tank shown on the left. The tube contains mercury, or water, or oil. One side of the tube is in contact with the fluid in the tank; the other is in contact with … Read more

Several simple instruments for the measurement of pressure make use of a column of liquid. A mercury barometer consisting of a tube of glass, about 1m long, closed at the upper end and open at the lower end. The tube is filled with mercury, except for a small empty space at the top. The bottom … Read more