A rocket travels in a trajectory given by the equation s = -4.9t 2 + v0t, where s is meters above ground, t is time in seconds and v0 is the initial velocity. If the intial velocity is 49 m/sec, after how many seconds will the rocket reach its maximum height?

a 5
b 10
c 15

Points j and k plotted on the coordinate grid are two vertices of rectangle jklm rectangle jklm has an area of 7 square units point j is located at 2,1 and point k is located at -5,1 each vertex of the rectangle is located at a point that has integer coordinates. what is the perimeter of rectangle jklm? (need answer asap)