You are conducting a calorimetry experiment using a calorimeter with 500mL of water in its outer chamber to determine the enthalpy of reaction of a chemical reaction. The initial temperature of the water is 25°C. After the reaction, the temperature of the water is 62.8°C. Disregarding any heat loss to the walls of the container, calculate the ΔHr0. The specific heat of water is 4.18J/(g•K).

your answer is c) plasma

~*"auba14"*~

(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