Final answer:
The work done on the truck is 19.6 Joules (J).
Step-by-step explanation:
To calculate the work done, we can use the formula W = F x d, where W is the work done, F is the force applied, and d is the distance traveled. In this case, the child pushes the toy truck with a force of 5.6 N and the truck travels a distance of 3.5 m. Plugging these values into the formula, we have W = 5.6 N x 3.5 m = 19.6 J (Joules).