Distance for which the balloon has been pulled by the child = 12 meter
Force applied by the child to pull the balloon = 1.0 Newton
The angle below horizontal = 60 degree
These information's are already given in the question. Based on the above information's the answer to the question can be easily determined.
We know that
Work done = Force * Distance * Cos(60)
= 1 * 12 * (1/2)
= 1 * 6
= 6 Joules
So the work done by the child is 6 joules. I hope the procedure is clear enough for you to understand. Based on the above mentioned procedure, you can always solve problems of similar kind without taking any outside help.
