A newly discovered planet has twice the mass of the Earth, butthe acceleration due to gravity on the new planet's surface isexactly the same as the acceleration due to gravity on the Earth'ssurface. What is the radius Rp of the new planet in terms ofthe radius R of Earth? a) Rp = (2) R b) Rp = 2 R c) Rp = (2/2) R d) Rp = 4 R e) Rp = (1/2) R A newly discovered planet has twice the mass of the Earth, butthe acceleration due to gravity on the new planet's surface isexactly the same as the acceleration due to gravity on the Earth'ssurface. What is the radius Rp of the new planet in terms ofthe radius R of Earth? a) Rp = (2) R b) Rp = 2 R c) Rp = (2/2) R d) Rp = 4 R e) Rp = (1/2) R
Explanation / Answer
accleration due to gravity g = GM / R ^ 2 Or g ' / g = ( M ' / M ) ( R / R ' ) ^ 2 1= ( 2M / M ) ( R / R ' ) ^ 2 from this new planet radius R ' = 2 *R