Moons revolve around a planet, and planets revolve around the sun. Ganymede is considered a moon because it revolves around the planet Jupiter, therefore, it is a moon. :) I hope this helps!
Answer:
Approximately 
(assuming that external forces on the cannon are negligible.)
Explanation:
If an object of mass 
is moving at a velocity of 
, the momentum 
of that object would be 
.
Momentum of the t-shirt:
.
If there is no external force (gravity, friction, etc.) on this cannon, the total momentum of this system should be conserved. In other words, if 
denote the momentum of this cannon:
.
.
Rewrite to obtain 
. Since the mass of this cannon is 
, the velocity of this cannon would be:
.
Answer:
2, High mass stars.
Add-on:
i hope this helped at all. im sorry if its incorrect.
Energy is the capacity to do some type of work
