The number of significant figures in 3.00 × 10⁸ is MCQ with Answer and Explanation

Explanation:
Apparent weight = m(g+a) = 60×12 = 720 N. In kg wt, 720/10 = 72 kg. So machine shows 72 kg. Downward acceleration would show less.

Explanation:
Escape velocity v_e = √(2GM/R), where M is planet mass, R its radius. Thus v_e depends on both M and R. It is independent of the escaping body's mass (as gravitational and inertial mass cancel). Memory tip: 'v_e ∝ √(M/R); larger M or smaller R ⇒ higher escape velocity'. This gravitation formula application is frequently tested in competitive exams. Always recall that escape velocity is a property of the planet, not the projectile. This problem assesses understanding of gravitational potential energy concepts.

Explanation:
c = 2.9979 × 10⁸ m/s, commonly 3×10⁸ m/s. In glass slower. It's a universal constant, maximum speed. Used in relativity, E=mc².