Supposed to Children's push horizontally, but exactly opposite directions, on a third child and wagon. The first child exhort exerts a force of 75.0 n, the second a force of 95.0 n, friction is 12.0 n, and the mass of the third child plus wagon is 21.0 kg. What is the system of interest if the acceleration of the child in the wagon is to be calculated? Check all that apply. The child in the wagon? The child outside the wagon? The wagon? Calculate the acceleration. What would the acceleration be if friction is 20.0?