Answer:
The value is [tex]bhp = 24 \ hp[/tex]
Explanation:
From the question we are told that
The velocity of the car is [tex]v = 60 \ mph[/tex]
Th amount of fuel used in an hour is [tex]a = 8 \ L = 8.0 *10^{-3} \ m^2/hr = \frac{8.0 *10^{-3}}{3600} = 2.22 *10^{-6} \ m^3 /s[/tex]
The heating value of the fuel is [tex]HV =42.4 MJ/kg = 42.4 *10^{6} J/kg[/tex]
The thermal efficiency of the engine is [tex]\eta = 25\%=0.25[/tex]
Generally the rate at which the fuel is consumed is mathematically represented as
[tex]\r Q = \rho * a[/tex]
Here [tex]\rho[/tex] is the density of fuel with value [tex]\rho = 750 \ kg /m^3[/tex]
[tex]\r Q = 750 * 2.22*10^{-6}[/tex]
=> [tex]\r Q = 1.667 *10^{-3} \ kg /s[/tex]
Generally the power available at the crankshaft axis is mathematically represented as
[tex]\r H_v = H_v * \r Q[/tex]
=> [tex]\r H_v = 42.4 *10^{6} * 1.667*10^{-3}[/tex]
=> [tex]\r H_v = 70668.08 \ W[/tex]
Converting to horse power
[tex]\r H_v = \frac{ 70668.08}{735}[/tex]
=> [tex]\r H_v = 96.15 \ hp[/tex]
Generally the power available in the crankshaft in break hoarse power is mathematically evaluated as
=> [tex]bhp = 96.15 * \eta[/tex]
=> [tex]bhp = 96.15 * 0.25[/tex]
=> [tex]bhp = 24 \ hp[/tex]
