1. The problem statement, all variables and given/known data From People's Physics Book, ch. 3: 2. Relevant equations For a. I got 23 m/s which is correct and b, 3.6 s which is correct as well. For c I chose the equation x(t)=x0+v0t+1/2at^2 3. The attempt at a solution And plugged things in like so... (where upwards is positive) x(t)=20m+12m/s*t+1/2(9.8m/s^2 )(t^2 ) And then I just started in plugging in times. 1 second was the highest x(t) value I could find, at 27.1 meters, but the book says the correct answer (max height) is 28 m. Am I missing something? Help with d would also be helpful. Additional question: Is there a resource for the people's physics book that has explanations for problems?