The mass and diameter of a planet are twice those of earth. The period of oscillation of pendulum on this planet will be (If it is a second's pendulum on earth)
As we know g = GMR2
⇒gearthgplanet=MeMp×R2pR2e⇒gegp=21
Also T ∝ 1√g⇒TeTp=√gpge⇒2Tp=√12
⇒Tp=2√2 sec.