Question: on the planet newtonia a simple pendulum having a bob...
On the planet Newtonia, a simple pendulum having a bob with a mass of 1.31 kg and a length of 188.2 cm takes 1.58 s , when released from rest, to swing through an angle of
11.5 ∘, where it again has zero speed. The circumference of Newtonia is measured to be 5.14×104 km .
What is the mass of the planet Newtonia? (in kg)