#Given:
bp = 100. #Brake power in kW
deltaT = 30. #Temperature raised of water in degreeC
p_p = 30
p_d = 26. #Percentage of energy going to coolent in petrol and diesel
eta_p = 26.
eta_d = 31. #Efficiency of petrol and diesel engine in percent
s = 4.1868 #Specific heat capacity of water in J/kgK
#Solution:
#Petrol engine
CW_p = bp*(p_p/100)/((eta_p/100)*deltaT*s) #Amount of cooling water required in petrol engine in kg/s
#Diesel engine
CW_d = bp*(p_d/100)/((eta_d/100)*deltaT*s) #Amount of cooling water required in diesel engine in kg/s
#Results:
print " Amount of cooling water required in petrol engine = %d kg/hr"%(CW_p*3600)
print " Amount of cooling water required in diesel engine = %.1f kg/hr"%(CW_d*3600)