One mole methane undergoes complete combustion in a stoichiometric amount of air. the reaction proceeds as ch, + 20, → co2 + 2h2o both the reactants and the products are in gas phase. ah, = - 730 kj/mol of methane. if the average specific heat of all gases and vapours is 40 j/mol k, the maximum temperature rise of the exhaust gases in k would be approximately equal to (a) 1225 (b) 1335 (c) 1525 (d) 1735

(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