Who proposed the theory of relativity? MCQ with Answer and Explanation

Explanation:
Objects float if their density is less than the fluid. Cork density < water density, so it floats. Iron sinks because density > water. Ship made of iron floats due to shape displacing more water, average density less.

Explanation:
Fusion: light nuclei (e.g., hydrogen) combine to form heavier nucleus (helium), releasing energy (stars, H-bomb). Fission splits heavy nuclei (U, Pu). Memory tip: 'Fusion = joining light; Fission = splitting heavy'. Nuclear reaction concept frequently tested in competitive modern physics sections.

Explanation:
A freely falling body falls under the sole influence of Earth's gravity (neglecting air resistance). Near the surface of the Earth, the acceleration due to gravity ('g') is constant (approximately 9.8 m/s²). Because the acceleration does not change during the fall, it is an example of uniform accelerated motion.