Answer:
the warm air would be up and cool would be down
Explanation:
warm air is less dense and cool air is more dense
Yes, because you would need friction to slow down the rollercoaster to a stop.
Answer:
19.2*10^6 s
Explanation:
The equation for time dilation is:

Then, if it is observed to have a life of 6*10^6 s, and it travels at 0.95 c:

It has a lifetime of 19.2*10^6 s when observed from a frame of reference in which the particle is at rest.