A ball is launched from 8 feet off the ground at an initial vertical speed of 64 feet per second. It is aimed across a field at a target also 8 feet off the ground. The height of the ball at time, t, in seconds, is given by the function, h = –16t 2 + 64t + 8. It will take the ball seconds to hit its target.

a

Step-by-step explanation:

because

The equation that is given, h = –16t 2 + 64t + 8, represents the general formula of the motion which is h(t) = h0 + v0t - 16t² where h0 is the initial height (8 feet), v0 is the initial velocity  (+64 ft/s) and t is time in seconds. To determine the time when the ball is at the maximum height, we need to determine the vertex of the parabola which is done as follows:

vertex = time at maximum height = -b/2a = -64 / 2(-16) = 2 seconds

The maximum height can be calculated by substituting the time we obtained to the function.

h = –16t 2 + 64t + 8

h = –16(2)^2 + 64(2) + 8 = 72 feet

Step-by-step explanation:

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)