The force required to keep a body moving in uniform velocity on a frictionless surface is MCQ with Answer and Explanation

Explanation:
Surface tension = force/length. Force dimensions [MLT⁻²], length [L], so [MLT⁻²]/[L] = [MT⁻²]. Also energy per area gives same dimensions: [ML²T⁻²]/[L²] = [MT⁻²].

Explanation:
Distance covered in nth second: sₙ = u + a(2n-1)/2. With u=0, sₙ ∝ (2n-1). For n=1: 2(1)-1=1; n=2: 3; n=3:5. Thus ratio 1:3:5. This result holds for any uniformly accelerated motion starting from rest. The distances covered in successive equal time intervals follow odd number ratio. Memory aid: This is a standard result derivable from s = ut + ½at² by calculating s at t=n and t=n-1. Frequently appears in competitive exams testing equation of motion applications.

Explanation:
In an open vessel, water boils at 100°C, and extra heat merely creates steam rather than raising the temperature. A pressure cooker traps steam, increasing the internal pressure above atmospheric pressure. Increased pressure raises the boiling point of water (often to around 120°C). Cooking the food at this higher temperature significantly reduces cooking time.