Answer: 217.52 N
Explanation: The applied force is 20 N, the distance covered is 12.0 m and the angle is 25° above the horizontal.
Hence the formulae that defines work done is given by
W = Force × distance
But since the force has been inclined at an angle θ above the horizontal, the horizontal component of force is neccesary to produce the required motion to make the child do work on the wagon.
Hence
Work done = (horizontal component of force) × distance
Work done = F cos θ × distance
Work done = 20 cos 25 × 12 = 217.52 N