98 points brainliest ! a ball is thrown from the top of a building. the function below shows the height of the ball in relation to sea level, f(t), in feet, at different times, t, in seconds: f(t) = -16t^2 + 32t + 90 the average rate of f(t) from t = 4 and t = 6 seconds is seconds. i think the answer is -128 ft per second. if that's right let me know and if it's not explain what you did.

The height of the ball as a function of t is given

f(t)=-16*t^2+32t+90

The velocity is the derivative of f(t) with respect to time (using calculus)

v(t)=f'(t)=-32t+32

(if you have not done calculus before, then use the kinematic equation

v(t)=v0+at=32-32t (given v0=initial velocity=32 ft/s, acceleration due to gravity=-32 ft/s^2)

The average velocity between t1 and t2 is given by

v=(v(t2)+v(t1))/(t2-t1),

Substituting t2=6 s., t1=4 s.

v=(v(6)+v(4))/(6-4)=(-160+(-96))/2=-256/2=-128

Therefore

your answer of -128 ft per second is correct.

Hello!

I believe you are correct, the answer is -128 fps.

I hope it helps!

i think the answer is b

1. sometimes

2.   never

3   .08c = 7.50+.05c   250 pages

step-by-step explanation:

1.   sometimes

the theoretical probability of rolling a 1 is 1/6.   perhaps you got really lucky and never rolled a 1   in those 60 times.   your experimental probability is 0.   or perhaps you rolled a 1   20 times.   your experimental probability is 20/60 is 1/3.     it really just depends on how you rolled in that experiment.

2.   never

the probability of the event occurring is 1.   that is being 100 % sure it will happen.   that is the maximum amount of confidence we have.

3.   no customer card cost:   .08 times number of pages

customer card cost:   7.50 + .05 times number of pages

we want to find when it costs the same amount, so we will set these equal

let c = number of pages

.08c = 7.50+.05c

subtract .05c from each side

.08c-.05c = 7.5+.05c-.05c

.03c=7.5

divide each side by .03

.03c/.03 = 7.5/03

c =250  

the cost is the same at 250 pages