Question

The escape velocity from the earth is 11.2km/sec. Another plant is having a mass 1000 times and radius 10 times that of the earth, then escape velocity at that planet will be ___________

(a) 11.2km/sec

(b) 112km/sec

(c) 1.12km/sec

(d) 1120km/sec

The question was posed to me by my college professor while I was bunking the class.

This intriguing question originated from Orbital Velocity in portion Kinetic Theory of Gases of Engineering Physics I

Answer 1

The correct answer is (b) 112km/sec

The explanation is: ve=√(2GM/R)=11.2km/sec

(ve)^‘=√((2G×100M)/(R/4))=2/9 √(2GM/R)

(ve)^‘=2/9×11.2=2.5km/sec.