Land breeze blows at night because MCQ with Answer and Explanation

Explanation:
When you pull a roller at an upward angle, the vertical component of the applied force acts strictly upwards, reducing the normal reaction (N = mg - Fsin_theta) and thus reducing friction (muN). When you push it at a downward angle, the vertical component adds to the weight (N = mg + Fsin_theta), increasing the normal reaction and consequently increasing the rolling friction.

Explanation:
Planck's constant h = E/ν, so its dimensions are [Energy]/[Frequency] = [ML²T⁻²]/[T⁻¹] = [ML²T⁻¹]. Angular momentum = mvr = M·LT⁻¹·L = [ML²T⁻¹]. Energy = [ML²T⁻²], linear momentum = [MLT⁻¹], force = [MLT⁻²]. Thus, Planck's constant and angular momentum share dimensions. This is a key dimensional match in quantum mechanics.

Explanation:
The relationship between phase difference (phi) and path difference (delta x) is given by the formula phi = (2pi / lambda) * delta x. Given a path difference of lambda / 2, substitute this into the formula: phi = (2pi / lambda) * (lambda / 2) = pi radians. This indicates strictly destructive interference.