Physics Quiz 6

Mesons are hadronic subatomic particles composed of an equal number of quarks and antiquarks, usually one of each, bound together by strong interactions. Outside the nucleus, mesons appear in nature only as short-lived products of very high-energy collisions between particles made of quarks, such as cosmic rays (high-energy protons and neutrons) and baryonic matter.

All objects, regardless of mass, will fall at the same rate. Heavier things have a greater gravitational force AND heavier things have a lower acceleration. It turns out that these two effects exactly cancel to make falling objects have the same acceleration regardless of mass.

The sounds having a frequency range of 20Hz to 20kHz are known as audible sounds. All the frequencies residing between the limit of 20Hz and 20KHz can be perceived by human beings.

The apparent weight of a man in a lift is less than the real weight when the lift is going down with an acceleration. When a lift accelerates upwards, the apparent weight of the person inside it increases; and when a lift accelerates downwards, the apparent weight of the person inside it decreases.

The spokes used in the wheel of a bicycle increase its moment of inertia due to the increase in the distribution of mass. This opposes the change in the rotary motion of the wheel. Thus spokes fitted to the cycle wheel give a steady motion.

Clay is a highly plastic substance. Clay particles are attracted to each other by weak electrostatic forces. Water conducts these forces. Thus, dry clay mixed with a fifth of its weight in water, becomes the plastic material clay artists use.

The centre of gravity of a sprinter during the race lies ahead of his feet. It is an imaginary point in a body of matter where the total weight of the body may be thought to be concentrated. Running with a lean allows gravity to pull the runner forward.

Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave.

Hypermetropia, also known as long-sightedness, is a defect of vision in which a person can't see the nearby object clearly (appears blurred), though can see the distant objects clearly. The near point of a hypermetropic eye is greater than 25 cm.

Cyanide breaks the electron transport chain (ETC) in human body. ETC is found within the mitochondria of living cells. It is the last component of aerobic respiration and is the only part of glucose metabolism that uses atmospheric oxygen. Cyanide prevents the cells of the body from using oxygen.