Question
Please HELP!
Calculate the change in entropy of 250g of water when it is heated from 10 degree C + 20 degree C. You can make an estimate by using an average temperature of 15 degree C during the process . B John and peter are 40 meters apart. They run towards each other along a straight path to give each other a hug. The speed or john is 5.3 m/s while the speed of peter is 4.7m/s. As they start to run, Peter?s dog leaves him and run towards John at 7.0 m/s. Upon reaching john, the dog runs towards peter and continues to run back and forth until they meet. What is the distance traveled by the dog when the two finally hug each other?
Explanation / Answer
S = dQ/T = m?Cp/T dT
=>
?S
= ? dS
T_final
= ? m?Cp/T dT
T_initial
= m?Cp?ln(T_final/T_initial)
= 250g ? 4.181 J/gK ? ln( (20 + 273.15)K / (10 + 273.15)K )
= 30.31 J/K