Mass is a measure of the amount of matter in an object. It is a scalar quantity, which means it has only magnitude and no direction. Momentum, on the other hand, is a vector quantity that has both magnitude and direction. It is defined as the product of an object's mass and velocity.
When an object is accelerated, its velocity changes. This means that its momentum also changes. However, the object's mass does not change. This is because mass is a fundamental property of matter that does not depend on its motion.
The energy of an object is also a vector quantity that has both magnitude and direction. It is defined as the work done on an object to change its motion. When an object is accelerated, its energy also changes. This is because work is done on the object to change its velocity.
So, while the mass of an object does not increase when it is accelerated in space, its momentum and energy do increase.
