1. The problem statement, all variables and given/known data In Example 2.6, we considered a simple model for a rocket launched from the surface of the Earth. A better expression for a rocket's position measured from the center of the Earth is given by Y(t)=(RE3/2+3(√g/2)REt)2/3 where RE is the radius of the Earth (6.38 ✕ 106 m) and g is the constant acceleration of an object in free fall near the Earth's surface (9.81 m/s2). Find Vy(t) and ay(t) using variables not numerical values. Then what is t when y=4RE Lastly find V and a at t = y @ 4RE 2. The attempt at a solution Naturally I found the first and second derivative of Y(t), which were not accepted by webassign (not correct nor incorrect). Then being stumped by that I decided to find t when y = 4RE, which also gave me an incorrect answer. I got Y'(t)=2/3(RE3/2+3√(g/2)REt)(-1/3)(3√(g/2)RE Y"(t)=-2/9(RE3/2+3√(g/2)REt)(-4/3)(3√(g/2)RE I also found a t value of 9.5947 when y = 4RE, this was found by just plugging in all the values in Y(t). I know I just posted a problem a day or to ago, but I've been beaten by this one aswell. Any advice on how to go about this would be a great help. Thank you.