a train is leaving the station and goes from 3m/s to 30 m/s in 12 s. The acceleration of the train is

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Which statements about these triangles is true

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"