Practice Online test 1 - general science mcq Online Quiz (set-1) For All Competitive Exams

As already We know that, when a particle is thrown vertically upward with a velocity u from a point A, the particle returns the point A with the same velocity u.

Now, using the fact $v^2=u^2+2gh$, we obtain $v^2=u^2+2g × {12u^2}/{g} ⇒ v^2 = u^2+24u^2$
⇒ v = 5u

1. CGS - centimetre-gram-seconds

The centimetre–gram–second system of units (abbreviated CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time.

2. SI - standard international system

S.I system (standard international system). In this system, the units of mass, length and time are the same, as that of the M.K.S system. However, it is an enlarged system encompassing all fundamental units.

3. MKS - metre-kilogramme-second

THE M.K.S. (metre-kilogramme-second) system of units is increasingly being. used by electrical engineers, particularly by those concerned with light-current and microwave work. The adoption of this system into the technical communications of physics and electrical engineering varies considerably.

4. FPS - foot-pound-second

The foot-pound-second (fps) system of units is a scheme for measuring dimensional and material quantities. The fundamental units are the foot for length, the pound for weight, and the second for time. The fps system has two variants, known as the American version and the Imperial version.

746 watts

A power level of 1 hp is approximately equivalent to 746 watts (W) or 0.746 kilowatts (kW). To convert from horsepower to watts, multiply by 746.

To convert from watts to horsepower, multiply by 0.00134.

Fundamental unit:

The SI unit of a fundamental quantity is called a fundamental unit.

There are 7 fundamental quantities and their fundamental units.
The fundamental quantities are Length, Mass, Time, Electric Current, Thermodynamic Temperature, Luminous Intensity, etc.
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Also know,

Fundamental Quantity:

An independent physical quantity that cannot be expressed in terms of other physical quantities is called fundamental quantity.
They are conventionally chosen. It is used as a base to get other derived quantities by combining them.

Supplementary units:

The units that are used along with base units to form derived units in the International System are called supplementary units.

Explanation for the question:

meter (m), kilogram (Kg) and second (s) are the fundamental units of fundamental quantities Length, Mass and Time respectively.

Where Newton (N) is a Derived Quantities.

Acceleration is the correct answer.

Acceleration Definition:

the act or process of moving faster or happening more quickly: the act or process of accelerating or ability to accelerate

• It is the time rate of change of velocity of a body.
• It is a vector quantity.
• Its SI unit is m/s².

The correct explanation for the problem:

When the coin toss, it also has the same velocity as the velocity of the train but during the time, the coin is in the air, the velocity of the train keeps on increasing, and hence it falls behind the passenger.

Definition for other options,

Speed :

Speed is defined as the rate of change of position of an object in any direction. It is measured as the ratio of distance to the time in which the distance was covered. It is a scalar quantity as it has only direction and no magnitude

Deceleration :

A decrease in speed as the body moves away from the starting point is defined as Deceleration. Deceleration is the opposite of acceleration. Deceleration also is known as negative acceleration.

Velocity :

Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time. Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies.

The SI unit of force is the newton, symbol N.

Newton :

Newton, an absolute unit of force in the International System of Units (SI units), abbreviated N. It is defined as that force necessary to provide a mass of one kilogram with an acceleration of one metre per second per second.

Faraday : 

A faraday is a dimensionless unit of electric charge quantity, equal to approximately 6.02 x 10²³ electric charge carriers.

Fermi :

Fermi ('unit of measurement') is an SI unit of length equal to 10⁻¹⁵ metres, which means a quadrillionth of one metre. This distance is sometimes called a fermi and was so named in honour of Italian-American physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.

Rutherford : 

The rutherford (symbol Rd) is a non-SI unit of radioactive decay. It is defined as the activity of a quantity of radioactive material in which one million nuclei decay per second. It is therefore equivalent to one megabecquerel, and one becquerel equals one microrutherford.