Questions

The trajectory of the bullet is a parabola

Dust particles such as coal dust(smoke) are fine particle of a solid (carbon in the case of smoke) dispersed in air. They are colloidal systems and the particles are charged either positive or negative. In an applied electrical field, they are attracted towards the opposite electrodes. Movement of the particles towards the electrodes is known as 'electrophoresis'. Hence electrophoresis is applied to remove smoke within the chimeny itself without allowing it to escape into the air and cause nuisance.

Scientists estimate the volume of blood in a human body to be approximately 7 percent of body weight. An average adult body with a weight of 150 to 180 pounds will contain approximately 4.7 to 5.5 liters of blood. An average child with a body weight of 80 pounds will have approximately half the amount of blood as an adult.

The amount of blood in a human body varies, depending on factors such as age, sex, overall health and even where a person lives. For example, men tend to have more blood than women of comparable size and weight.

Interestingly, people who live at high altitudes may have up to two liters of extra blood compared to those who live at lower altitudes. Because the air at higher altitudes has less oxygen, people who live at high altitudes need extra blood to deliver the right amount of oxygen to their lungs.

We know that 1 Pint = 0.473 liters

Hence, an average amount of blood in the human body = 4.7 - 5.5 lit = 10 - 12 pints.

A typical giraffe neck can stretch as long as six feet, the giraffe's tongue usually measures 18-20 inches long.

Why that much long:

Giraffe's eat Acacia tree leaves. The acacia tree's tasty leaves are protected by very sharp thorns. The giraffe's long tongue allows it to reach the highest, tastiest leaves while avoiding the sharp thorns. Its tongue also features a thick, tough layer that protects it from being cut by the thorns. If a giraffe's tongue does get cut by a thorn, its extra-thick saliva has antiseptic properties that help it to heal quickly.