Answer:
The change of the volume of the device during this cooling is 
Explanation:
Given that,
Mass of oxygen = 10 g
Pressure = 20 kPa
Initial temperature = 110°C
Final temperature = 0°C
We need to calculate the change of the volume of the device during this cooling
Using formula of change volume


Put the value into the formula



Hence, The change of the volume of the device during this cooling is 
I’m lost at this question, sorry but I would’ve help !
Answer:
E_{k2}=2660 [J] kinetic energy.
Explanation:
The energy in the initial state i.e. when the rollercoaster is at the top is equal to the energy in the final state i.e. when it is at the bottom of the hill.
These states can be represented by means of the second equation.
![E_{k1}+E_{p1}=E_{k2}\\160 + 2500 = E_{k2}\\E_{k2}=2660 [J]](https://tex.z-dn.net/?f=E_%7Bk1%7D%2BE_%7Bp1%7D%3DE_%7Bk2%7D%5C%5C160%20%2B%202500%20%3D%20E_%7Bk2%7D%5C%5CE_%7Bk2%7D%3D2660%20%5BJ%5D)
Since the rollercoaster is located in the bottom of the hill where the potential energy level is zero, therefore there is only kinetic energy in the second state.
The second runner must run 3.3m/s. If the leading runner is 1.5 seconds ahead and there are 30m left, the second runner would need to run slightly faster than the lead in order to finish at the same time. To calculate this I did 30/1.5 which gave me 0.05. I added this onto the speed of the lead runner to get 3.3m/s :)