A smart-phone is thrown upwards from the top of a 240-foot building with an initial velocity of 32 feet per second. The height h of the smart-phone after t seconds is given by the quadratic equation
h = - 16t2 + 32t + 240. When will the smart-phone hit the ground?

t = 5 sec

Step-by-step explanation:

h = - 16t² + 32t + 240

On the ground h = 0.

- 16t² + 32t + 240 = 0 / : (- 16)

t² - 2t - 15 = 0

(t-5)(t+3) = 0

t = 5, t = - 3

Time can be only positive, so t = 5 sec

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.