Question 1159700
when it hits the ground -5t^2+10t+2=0
or 5t^2-10t-2=0
t=(1/10)(10+/-sqrt(100+40))
t=(1/10) (10+/-11.83)
=2.183 seconds

The longer time is the solution for the second part, which is when -5t^2+10t+2=3
or -5t^2+10t-1=0
or 5t^2-10t+1=0
or t=(1/10)(10+/- sqrt(100-20))
the solutions are 0.106 seconds (going up) and 1.894 sec (going through rim)

{{{graph(300,300,-4,4,-10,10,-5x^2+10x+2,3)}}}