Answer:
after 4 seconds
Step-by-step explanation:
Given
h = 20 - 5(t - 2)²
When rocket is on ground then h = 0
Equate to zero and solve for t
20 - 5(t - 2)² = 0 ( subtract 20 from both sides )
- 5(t - 2)² = - 20 ( divide both sides by - 5 )
(t - 2)² = 4 ( take the square root of both sides )
t - 2 = ± = ± 2 ( add 2 to both sides )
t = 2 ± 2
Thus
t = 2 - 2 = 0 ← when rocket is launched
t = 2 + 2 = 4 ← when rocket hits the ground
The rocket reaches the ground after 4 seconds
Answer: 38 in.^{2}
Step-by-step explanation:
1/ Find the area of the triangular sides. (1/2 x 2 x 6 = for each triangular side)
2/ Find the area of each of the rectangular sides. In this case, the bottom (base) side is 2x6 = . The rectangular side on the left is 2x3 =
, and the rectangular side on the right is 4x2 =
.
3/ Add everything together. Rectangular Sides + Triangular Sides = Surface Area --->
4/ You have your answer, now hope it helps ! :)
