Answer:
15 J
Step-by-step explanation:
Total energy before work will be from the sum of both kinetic and potential energy hence 25+15=40 J
Similarly, the total energy after work will be given by the sum of kinetic and potential energy. This will be 25+30=55 J
The difference of the two gives the amount of work done hence 55-40=15 J
Therefore, work done which is as a result of energy increase in the system is equivalent to 15 J