In a piston, the addition of 14.37 kj of heat to a 100. g sample of a liquid at a constant temperature of 35.2 °c caused the liquid to vaporize (change to a gas). the vaporized gas expanded against an external pressure of 1.07 atm and a volume change of 11.49 l was observed. (recall: 1 l• atm = 101.3 j} what was the change in the internal energy of the system, (ae in kj)? (enter your answer with two decimals places and no units.)

Answer : The change in internal energy of the system is 15.62 kJ

Explanation :

First we have to calculate the work done of the system.

where,

w = work done

P = external pressure = 1.07 atm

= change in volume = 11.49 L

Now put all the given values on the above formula, we get:

  (as per conversion)

Now we have to calculate the change in internal energy of the system.

As per first law of thermodynamic,

where,

= internal energy of the system

q = heat added to the system  = 14.37 kJ

w = work done of the system  = 1.25 kJ

Now put all the given values in the above formula, we get:

Hence, the change in internal energy of the system is 15.62 kJ

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied