We use the following formula to determine our acceleration:

We normally use letters in this formula, which gives us:

Filling in this formula gives us:
Δv (change of velocity) = 12 - 4 = 8 m/s
t = 1s

So our answer: the acceleration is
Answer:
For 6 its D
For 7 its A
For 8 its C
For 9 I think its B but Im not sure
Answer:
the internal energy of the mixture at final state = 238kJ/kg
Explanation:
Given
V= 0.6m³
m=5kg
R=0.287kJ/kg.K
T=320 K
from ideal gas equation
PV = nRT
where P is pressure, V is volume, n is number of mole, R is ideal gas constant , T is the temperature.
Recall, mole = mass/molar mass
attached is calculation of the question.