What is the only known perfectly round natural object in the universe?

Sun

Explanation:

Sun is considered to be the Perfectly round natural object in the universe.

The bulging effect in sun is almost zero i.e. the difference in its diameter at Poles and equator is only 10 km which proves that the sun is the most spherical object in the universe. Bulging effect is seen at equators i.e. slightly saucer-shaped due to the high spin of Stars or Planet but this effect is almost nil in sun.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.