A pilot of a helicopter plans to release a bucket of water on a forest fire. The height y in feet of water t seconds after its release is modeled by y = − 16 t 2 − 2 t + 400 . How long will it take for the water to reach the ground? Round to one number after the decimal point.

4.93 seconds

Step-by-step explanation:

The height y in feet of water t seconds after its release is given by the equation as follows :

We need to find the taken taken for the water to reach the ground. When it reach the ground, y will be equal to 0. So,

Above is a quadratic equation whose solutions can be calculated as follows :

Neglecting negative value.

Hence, it will take 4.93 seconds for the water to reach the ground

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.