Answer to Question #190087 in Physics for Daniel

Question

 A certain battery runs a toy truck and becomes partially discharged. In the process, it performs a total of 117 J of work on its immediate surroundings. It also gives off 3 J of heat,  which the surroundings absorb. No other work or heat is exchanged with the surroundings.

1. Provide values for and explain the sign allocated to each variable.                                                         

Answer 1

$$Q=-3\ J\\W=-117\ J$$

$$\Delta U=Q+W=-3-117=-120\ J\\$$