Tag: science & technology

Final velocity can be calculated using two different kinematic equations: v = u + at (requires initial velocity, acceleration, and time) or v² = u² + 2as (requires initial velocity, acceleration, and distance). Both methods B and C are valid ways to find final velocity, depending on what information is given.

When a body is at rest, its initial velocity is indeed 0 m/sec. This is a fundamental concept in kinematics - rest means no motion, which means zero velocity. This is the starting point for most kinematics problems.

The acceleration due to gravity g in the FPS (Foot-Pound-Second) system is approximately 32.17 ft/s². This is equivalent to 9.81 m/s² in the SI (metric) system. The FPS system uses feet and seconds as base units, so the numerical value differs from the more familiar 9.81.

The acceleration due to gravity in FPS (Foot-Pound-Second) system is 32.17 ft/s². Option A (9.81) is the value in SI/MKS system (m/s²), which is a common point of confusion. The FPS system uses feet as the unit of length, so the value must be larger numerically.

Atoms consist of three basic particles: protons (positively charged in the nucleus), neutrons (neutral in the nucleus), and electrons (negatively charged orbiting the nucleus). These fundamental particles determine an atom's properties. Molecules (option D) are formed when atoms bond together, not basic particles of atoms.

Dmitri Mendeleev is credited with inventing the modern periodic table in 1869. He arranged elements by increasing atomic mass and left gaps for undiscovered elements, demonstrating remarkable predictive power. While others like Lavoisier and Cannizzaro contributed to chemistry, Mendeleev's periodic table was the breakthrough that established the modern system.

Sodium (Na) is an alkali metal from Group 1 of the periodic table. Alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium. Iron (Fe), Nickel (Ni), and Cobalt (Co) are transition metals, not alkali metals. Therefore, only option A is correct.

CO2 and methane are both greenhouse gases that trap heat in Earth's atmosphere through the greenhouse effect. Nitrogen (N2) is not a greenhouse gas as it doesn't absorb infrared radiation, while sulphates actually have a cooling effect by reflecting sunlight back into space.

Global warming causes Arctic ice shrinkage, spreads tropical diseases like malaria and dengue, and increases extreme weather frequency. However, it does not affect Earth's rotational speed, which is governed by geological and astronomical factors like tidal forces and mass distribution.

One gigabyte (GB) equals approximately 1 billion bytes. In decimal notation used by storage manufacturers, 1 GB = 1,000,000,000 bytes, though in binary computing it's 2^30 = 1,073,741,824 bytes.