810 because multiplying it all adds up to 810
V≈2714.34ft³I hope this answer your question.
Answer:
4n-2
Step-by-step explanation:
subtract 6n-2n
and then subtract 5-3
you get 4n-2
your answer will be 4n-2
Basically when the object hits the ground, f(t) is equal zero. So all you need to do is to solve the quadratic equation:
-5t^2 + 20t + 60 = 0
D = b^2 - 4ac = 20^2 - 4 × (-5) × 60 = 400 + 1200 = 1600
t1 = (-b + sqrt(D)) / 2a = (-20 + 40) / (-10) = -2
t2 = (-b - sqrt(D)) / 2a = (-20 - 40) / (-10) = 6
Since time can't be negative, our solution is t2.
So the object will hit the ground in 6 seconds.
