9 public questions tagged with this topic.
g(d) = g(1−d/RE). d = RE/5, g(d) = 9.8(1−1/5) = 9.8×4/5 = 7.84m/s2. Mass: m = 245/9.8 = 25kg. Weight: W = 25×7.84 = 196N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 196 N. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g decreases above (option 1 correct) and below (option 3 correct) the surface, and is zero at the center (option 2 correct). Option 4 is incorrect as g is maximum at the surface, not below.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g(d) = g0(1−d/RE). 6.86 = 9.8(1−d/RE). 1−d/RE = 0.7. d/RE = 0.3. d = 0.3×6.4×106 = 1.92×106m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.9 × 10⁶ m. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g(h) = g(1+h/RE)2. h = RE/6, 1+h/RE = 1+1/6 = 7/6. g(h) = 9.8(7/6)2 = 9.8×3649 = 7.2m/s2. Mass: m = 392/9.8 = 40kg. Weight: W = 40×7.2 = 288N.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g(d) = g0(1−d/RE). 7.35 = 9.8(1−d/RE). 1−d/RE = 0.75. d/RE = 0.25. d = 0.25×6.4×106 = 1.6×106m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.6 × 10⁶ m. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g(d) = g(1−d/RE). d = RE/4, g(d) = 9.8(1−1/4) = 9.8×3/4 = 7.35m/s2. Mass: m = 196/9.8 = 20kg. Weight: W = 20×7.35 = 147N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 147 N. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
g(d) = g(1−dRE). At d = RE/2, g(d) = 9.8(1−RE/2RE) = 9.8×0.5 = 4.9m/s2. Mass: m = Wg = 989.8 = 10kg. Weight at depth: W = mg(d) = 10×4.9 = 49N.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
At Earth’s center (r = 0), the gravitational force from all surrounding mass cancels out due to symmetry, reducing g to zero, as g(d) = g(1−d/RE) becomes zero when d = RE.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
Above the surface, g decreases as g(h)∝1/(RE+h)2. Below the surface, only the mass inside a radius r
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
