Time

In physics, time is described by its measurement: time is the reading on a clock.  It is a scalar quantity (typically expressed by the symbol t) in classical, non-relativistic physics, and, like length, mass, and charge, is frequently characterized as a fundamental quantity. Other concepts such as motion, kinetic energy, and time-dependent fields can be derived mathematically by combining time with other physical quantities.

The second is the time unit in the International System of Units (SI) (symbol: s). Since 1967, it has been defined as the radiation corresponding to the transition between two hyperfine states of the caesium 133 atom’s equilibrium state for a total of 9,192,631,770 [cycles]. The functioning of a caesium atomic clock provides the basis for this definition. After around 1955, these clocks proved practicable for use as major reference standards, and they have been in use ever since.

Projectile motion

When a particle is hurled obliquely near the earth’s surface, it follows a curved route with constant acceleration that leads to the earth’s centre (we assume that the particle remains close to the surface of the earth). The path of such a particle is called a projectile, and its motion is called projectile motion.

In projectile motion, two separate rectilinear motions occur at the same time:

• Along the x-axis: uniform velocity, which is the reason behind the particle’s horizontal (forward) motion.
• Along the y-axis: uniform acceleration, which is the reason behind the particle’s vertical (downwards) motion.

A particle’s horizontal and vertical projectile motions are accelerated in the following ways: When a particle is sent into the air at a certain speed, the only force acting on it during that period is gravity’s acceleration (g). This downward acceleration has a vertical component. There is no acceleration in the horizontal direction, implying that the particle’s velocity in that direction remains constant.

Time of flight

The time between when the object is projected and when it reaches the surface is known as the time of flight of the projectile. The amount of the starting velocity and the angle of the projectile determine the time of flight.

Formula for calculating time of flight of a projectile is:

T=2usin θ ⁄ g

Here, T is the time of flight, u is the initial velocity of the projectile, is the angle of the projectile with the horizontal and g is the gravitational acceleration.

Maximum height of projectile

The object’s greatest height is determined by its highest vertical location during flight. The range of the projectile is the total distance covered by the projectile in horizontal direction. The projectile’s range is dependent on the object’s starting velocity.

The formula that is used for calculating the maximum height attained by the projectile is:

H=u²sin²θ ⁄ 2g

Here, u is the initial velocity, is the angle and g is the gravitational acceleration.

Range of projectile

The horizontal displacement of the projectile determines its range. Gravity only acts vertically, hence there is no acceleration in this direction. The range of the projectile, like its time of flight and maximum height, is a function of its initial speed.

The formula for calculating the range of projectile is:

R=u² 2θ ⁄  g

Here, R is the range of the projectile, u is the initial velocity, is the angle of initial velocity and g is the gravitational acceleration.

Unit of time

Any specific time interval that is utilised as a standard manner of measuring or expressing duration is referred to as a unit of time. The second, defined as around 9 billion oscillations of the caesium atom, is the base unit of time in the International System of Units (SI) and, by extension, most of the Western world. The National Institute of Standards and Technology’s exact current definition is: The SI unit of time is denoted by the symbol s.

Conclusion

Even physicists believe that time is one of the most challenging properties of our universe to comprehend. Physics is the only science that expressly analyses time. Even in the most advanced and complicated physical theories, time is commonly seen as an ontologically “fundamental” or main concept that is not comprised of or dependent on anything else.

Most scientists agree that time began with the Big Bang 13.8 billion years ago, and that it is calculated from, and indeed began with, that event. Whether, how, and when time will cease in the future is a more open subject, as it depends on various ideas about the universe’s ultimate fate and other mind-bending ideas such as the multiverse.