Question

Plz someone help!!!

A rock is thrown vertically upward from the ground, with an initial velocity of 64 ft/sec. Its position function is s(t) = –16t^2 + 64t. What is its velocity in ft/sec when it hits the ground?

0
–64
–32
–16

Answer 1

plz help me I am really stuck would the answer be 0?

Answer 2

A. i think

Answer 3

thx @slipknot how about this one?
Use the graph of f "(x) below to state x-coordinates of the inflection points for the graph of f(x).

graph is an inverted parabola with x intercepts at x equals 0 and x equals 4 and vertext at x equals 2.

0 only
4 only
0 and 4
2 only

Answer 4

A water tank has the shape of an inverted right circular cone with base radius 3 meters and height 6 meters. Water is being pumped into the tank at the rate of 12 meters3/sec. Find the rate, in meters/sec, at which the water level is rising when the water is 2 meters deep. Give 2 decimal places for your answer. Type your answer in the space below. If your answer is a number less than 1, place a leading "0" before the decimal point (ex: 0.35).

Answer 5

C.

Answer 6

for the next one

Answer 7

I am not really sure for the next one, could you walk me through it?

Answer 8

lol i dont know either x'd give meh a sec

Answer 9

let the radius of the water level be r m
let the height of the water be h m

make a sketch and by similarity:
h/r = 6/3
h/r = 2
h = 2r or r = h/2

V = (1/3)π r^2 h
= (1/3)π (h^2/4)(h) = (1/12)π h^3

dV/dt = (1/4) h^2 dh/dt
so when h= 2 and dV/dt = 12

12 = (1/4)((4)dh/dt
dh/dt = 12 m/sec

Answer 10

there u go

Answer 11

i'm sorry but I can't use that. It's not right.

Answer 12

x'd well its wut google said

Answer 13

do you know the correct answer?

Answer 14

um...no x'd

Answer 15

well, I submit my test and got a 77%, I missed 5.