"Lightyear" is a <em>distance</em> ... specifically, the distance that light travels
through vacuum in one year of 365 days.
It's equivalent to 9.454 x 10^12 kilometers, or 5.875 x 10^12 miles .
Option (a) is correct.
Falling objects accelerate as they approach the ground.This is because of the force of gravity acting on the falling objects. so the velocity of these objects increases continuously as they approach the ground. the acceleration acting on the falling objects is a constant ( close to the surface of earth) and is called as acceleration due to gravity denoted by g. value of g=9.8 m/s².
We have no idea. There are probably many things involved ... the planet's mass,
the availability of small bodies in the neighborhood that can be captured, etc.
950kg. It is W=mg. therefore, mass= W/g which is W/10
=9500/10
=950