A body moves along a straight line with v = 2t + 3. Acceleration after 2 s is MCQ with Answer and Explanation

Explanation:
Horizontal range R = u²sin(2θ)/g. sin(2θ) is maximum (value 1) when 2θ = 90° ⇒ θ = 45°. Thus maximum range at 45° projection angle, assuming same initial speed and level ground. Memory tip: 'Max range at 45°; max height at 90°'. This standard projectile motion result is frequently tested in competitive exams. Always verify assumptions: no air resistance, uniform gravity, launch and landing at same height. For different heights, optimal angle differs.

Explanation:
PE at top = mgh = 10×10×5 = 500 J, converted to KE = 500 J (assuming no air resistance).

Explanation:
Elastic potential energy stored in a stretched/compressed spring is ½kx², where x is displacement from equilibrium. This is work done against spring force which is average force times displacement. Work = ½Fx = ½(kx)x = ½kx². Similar to capacitor energy ½CV².