Gravitational potential energy: A 910-kg object is released from rest at an altitude of 1200 km above the north pole of the earth. If we ignore atmospheric friction, with what speed does the object strike the surface of the earth? (G = 6.67 × 10^-11 N ∙ m²/kg², M_earth = 5.97 × 10²⁴ kg, the polar radius of the earth is 6357 km) A) 4.5 km/s B) 2.2 km/s C) 2.7 km/s D) 3.2 km/s E) 4.8 km/s

Question

Quizplus · Accepted Answer

The gravitational potential energy at the initial altitude and at the Earth's surface can be used to find the change in potential energy, which equals the kinetic energy at impact. Using the formula for gravitational potential energy and solving for velocity, the speed is approximately 4.5 km/s.

Gravitational Potential Energy: a 910-Kg Object Is Released from Rest