Answer:
To correct the error in the equation E = 25 kJ + 7 kJ/kg, we need to address the inconsistency in the units. The unit "kJ/kg" represents energy per unit mass, while the unit "kJ" represents total energy. This discrepancy suggests that the person may have incorrectly combined terms with different meanings.
To fix this error, we need to ensure that all terms in the equation have the same units. We can either convert the given energy per unit mass (7 kJ/kg) to total energy or convert the total energy (25 kJ) to energy per unit mass.
Method 1: Converting Energy per Unit Mass to Total Energy:
If we assume a mass value (m), we can multiply the given energy per unit mass (7 kJ/kg) by the mass (m) to get the total energy contribution. This would result in correcting the equation as follows:
E = 25 kJ + (7 kJ/kg) * m, where "m" represents the mass.
Method 2: Converting Total Energy to Energy per Unit Mass:
If we assume a constant mass (m) for the system, we can divide the given total energy (25 kJ) by the mass (m) to obtain the energy per unit mass. This would result in correcting the equation as follows:
E/m = (25 kJ + 7 kJ/kg), where "E/m" represents the energy per unit mass.
The cause of this error could be a misunderstanding or misapplication of the units or a mistake during calculation. It's important to carefully consider the meaning and compatibility of units when manipulating equations involving physical quantities to avoid such errors. Checking units at each step of the calculation can help identify and rectify any inconsistencies or mistakes.