Two waves of identical frequency and amplitude superimpose in the same medium. If they meet perfectly in phase (crest meets crest), the resulting amplitude is: MCQ with Answer and Explanation

Explanation:
F = m×a. New force F' = (2m)×(a/2) = m×a = F. So force remains unchanged. This is direct proportionality. Understand the relationship: doubling mass doubles force, halving acceleration halves it, net effect no change.

Explanation:
3.600 has 4 significant figures (3,6,0,0). Trailing zeros after decimal are significant due to precision.

Explanation:
Materials are classified by their magnetic properties. Ferromagnetic materials (Iron, Cobalt, Nickel) are strongly attracted to magnets. Paramagnetic materials (Aluminum, Platinum) are weakly attracted. Diamagnetic materials (Water, Bismuth, Copper, Gold) are actually weakly repelled by a magnetic field because they create an induced magnetic field in opposition to the externally applied one.