The speed of sound in air at 0°C is approximately 332 m/s. At 27°C, it will be approximately: MCQ with Answer and Explanation

Explanation:
Work done = F·s = Fs cosθ. Coolie applies vertical force to support weight, displacement horizontal, angle 90°, cos90°=0, work zero. No displacement of force direction. Pushing wall: displacement zero, also zero work. But option A is standard example. Pushing wall also zero, but question expects one answer. I'll adjust: I'll remove 'pushing a wall' to avoid ambiguity. I'll replace with 'A satellite revolving around Earth in circular orbit' etc. However, here I'll keep A, note that pushing wall also has zero displacement, but the question lists specific cases, only one may be correct. Actually, in pushing wall, wall doesn't move, work zero, but often they consider pushing wall as no work. However, option D 'Pushing a wall' might also be zero. To avoid two correct, I'll change D to 'Throwing a ball upward' so only A is zero. I'll modify the question: D: 'Throwing a ball upward' (work positive). So answer A. Let's do that.

Explanation:
Gamma rays have wavelengths < 10⁻¹² m, shortest in EM spectrum. X-rays 10⁻¹⁰-10⁻⁸ m. UV 10⁻⁸-4×10⁻⁷ m. IR longer. So gamma rays shortest. Highest frequency, energy.

Explanation:
Rayleigh scattering of sunlight by air molecules, blue scattered most.