A projectile is fired with velocity u at angle 45° with horizontal. Its time of flight is (g = 10 m/s²) 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:
v_esc ∝ √(1/R). If R→R/4, v_esc ∝ √(4) = 2. So 2v_e.

Explanation:
Gamma rays highest frequency >10¹⁹ Hz, shortest wavelength. X-rays next. Radio lowest frequency. Frequency increases: Radio, microwave, IR, visible, UV, X-ray, gamma.