An object is thrown vertically upward with a speed of 19.1 m/s. How high does it rise?

I get 1.86e+01 m

How long does it take to reach this highest altitude?

I get 1.95e+00 s

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I am stuck on part c, however, which asks How long does it take the object to hit the ground after it reaches the highest altitude?

It takes the same time as it did going upwards.

OR you can dwork it out..final position is zero, intial position is zero..

hf=hi+vi*t+ 1/2 g t^2 where g is -9.8m/s^2
solve for t.