Gravitation

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Centripetal force acts towards the center of the circular path. This force is provided by friction between tires and road. Without it, the car would move straight due to inertia. Formula: Fc = mv²/r…

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Uniform circular motion is motion of a body with constant speed in a circular path. Examples: (1) Moon revolving around Earth, (2) Hands of a clock, (3) Stone tied to string being rotated. The velocit…

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The moon is in continuous free fall towards Earth, but its forward motion creates a circular orbit. The gravitational force provides exactly the right centripetal force needed for circular motion. Wit…

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Using F = GM₁M₂/d²: F = (6.67 × 10⁻¹¹ × 50 × 50)/(2²) = (6.67 × 10⁻¹¹ × 2500)/4 = 4.17 × 10⁻⁸ N. This tiny force explains why we don't feel gravitational attraction to nearby objects.

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Every body in the universe attracts every other body with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Formula: F…

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The force becomes 1/4th (one-fourth) of the original value. Since F ∝ 1/d², when distance doubles (2d), force becomes F/(2²) = F/4. This inverse square relationship explains why gravitational effects …

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In vacuum, only gravitational force acts on objects. Since g = GM/R² (independent of object's mass), all objects have same acceleration. On Earth with air, air resistance affects light objects like fe…

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Using s = ut + ½gt²: 45 = 0×t + ½×10×t², 45 = 5t², t² = 9, t = 3 seconds. The stone takes 3 seconds to reach the ground. Note: initial velocity u = 0 for dropped objects.