Physics

A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 12 Hz.

The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection.

A fan produces a feeling of comfort because our perspiration or sweating evaporates rapidly. Our body tries to cool ourselves by releasing sweat through pores of our skin. And when we sit under the fan, the sweat of our body evaporates due to directed air upon us making our body cool.

Electric charge has the dimension electric current time. The SI derived unit of electric charge is the coulomb, which is defined as an ampere second.

When a vibrating tuning fork is placed on a table, then a large sound is heard due to the entire system begins vibrating and forces surrounding air particles into vibration motion. The tendency of one object to force another adjoining or interconnected object into vibration motion is referred to as a forced vibration.

Solar energy is any type of energy generated by the sun. Solar energy is created by nuclear fusion that takes place in the sun. Fusion occurs when protons of hydrogen atoms violently collide in the sun’s core and fuse to create a helium atom.

Strong Nuclear Force is the force that binds the neutrons and protons in a nucleus.

Parabola, because when the coin is dropped at a particular point, it has the same velocity as the running train. So, by Newton’s first law, it continues its motion horizontally with that velocity. But then, it is also pulled down by earth’s gravity continuously. In this situation its horizontal motion gives way to the parabolic motion until it reaches the ground.

Energy is released during respiration.