to the right
Explanation:
The balls collide in a completely inelastic collision, in other words they have the same velocity after the collision, this velocity has a magnitude V.
We need to use the conservation of momentum Law, the total momentum is the same before and after the collision.
In the axis X:
(1)
To test this hypothesis, you changed the TEMPERATURE of the gas between 0 and 100°C
(273 and 373 K) and calculated the resulting VOLUME of the gas.
Therefore the independent variable was TEMPERATURE and the dependent variable was VOLUME