Momentum is one of those things that are 'conserved' (like energy). That means the total amount of momentum in an isolated system is the same after some event as it was before the event.
Before the ear-splitting explosion, while the firecracker and the billiard balls were just sitting there on the frictionless table, the momentum of the system was zero, because nothing was moving. Right there, that tells us that the total momentum of all the balls and the fragments of the firecracker ... if you add up all the momentum vectors AFTER the explosion ... the sum is still zero. (D)
-- From the point of view of an observer on Earth, the moon's orbit is an ellipse
with the Earth's center at one focus.
-- From the point of view of an observer on the sun, or on any other planet,
the moon's orbit is an ellipse with the sun at one focus, and perturbed by being
near the Earth.
Answer:
36.29 m/s
Explanation:
We know from theory that 
. Let's replace the value we know in our equation and solve for the only value left.
Iron nails are attracted to the magnet
