A water rocket is projected vertically upward from the ground. Its a height(h) m above the ground after t seconds is given by h=20-5(t-2)^2. When will the rocket reach the ground?
MARKING THE BRAINLIEST

The rocket will reach the ground after 4 seconds

Step-by-step explanation:

When the water rocket reaches the ground, the height, h will be zero.

⇒ h = 20 - 5(t - 2)²

⇒ 0 = 20 - 5(t - 2)²

⇒ 5 (t - 2)² = 20

⇒ (t - 2)² = 4

⇒ t - 2 = √4 = 2

∴ t = 2 + 2 = 4 seconds

h

step-by-step explanation:

your answer is 23/2 - 13.5

step-by-step explanation:

7/2 evaluates to

multiply x and 4.5

multiply x and 1

the x just gets copied along.

the answer is x

x

4.5*x evaluates to 4.5x

multiply 3 and 4.5x

multiply 1 and x

the x just gets copied along.

x

4.5*x*3 evaluates to 13.5x

7/2-4.5*x*3 evaluates to

  + 8 =

the answer is

7/2-4.5*x*3+8 evaluates to