On a hypothetical exoplanet

PHYSICS · Multi-part · CBSE · Physics · Gravitation · Gravitation

Problem

On a hypothetical exoplanet, careful experiments reveal that for every object the gravitational mass is 1.0 % larger than its inertial mass, while all other physical laws (including the value of the universal gravitational constant GG) remain the same as on Earth. A researcher releases a rock of inertial mass mim_i from rest at height hh above the planet’s surface, where the local gravitational field produced by the planet alone would have magnitude g0g_0 if the two masses were exactly equal. (a) Derive an expression for the rock’s free-fall acceleration afalla_\text{fall} in terms of g0g_0 and the 1.0 % mass discrepancy described above. (b) When the rock has fallen halfway to the ground (distance h/2h/2), determine the ratio of its gravitational potential energy change to the kinetic energy gained, expressed in terms of the 1.0 % discrepancy. (c) Describe two observable consequences or paradoxes that inhabitants of this planet might notice in everyday life if inertial and gravitational mass differed by 1.0 %.

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