Question

If a ball is thrown straight up into the air with an initial velocity of 80 ft/s, its height in feet after t second is given by y=80t−16t^2.

a) Find the average velocity for the time period begging when t=2 and lasting

(i) 0.1 seconds...... i.e., over the time interval [2,2.1]

(ii) 0.01 seconds

(iii) 0.001 seconds


b)Estimate the instantaneous velocity of the ball when t=2.

Answer 1

i got 14.4 for i

Answer 2

radar i think i got it all except b

Answer 3

actually (iii), i need help with that

Answer 4

80-64=14 fps.......wouldn't that be the answer
the initial velocity minus the reduced velocity (due to gravity)

Answer 5

using the derivative of dh/dt d' of 80t-16t^2 = 80-32t

Answer 6

plug in t=2.

Answer 7

I think part a is the most difficult, good luck with this

Answer 8

got it thanks

Answer 9

radar do you about limits?

Answer 10

as x is approaching a number, that type of limit?

Answer 11

not to much, I do agree with you on the 14.4 for a i
for the limit please state the function of x and see if I can figure it out

Answer 12

looking at this graph, im supposed to determine a bunch of limits

first x as it approaches 1 from left
then as x approaches 1 from right
as x approaches 1
f(1)
as x approaches 2 from left
as x approaches 2 from right
as x approaches 2
f(2)

Answer 13

Sorry, but not much help here the function looks to be discontinous at a couple of points. Better post that and get a lot exposure for it lol

Answer 14

ok thanks

Answer 15

what about this
Given that f(x)=x^2−7x and g(x)=x−5, calculate
f of g
g of f
f of f
g of g

Answer 16

Here is my wag on f(1) 0 as x approaches 1 from the left
0 as x approaches 1 from the right
0 as x approaches 1
f(2) 2 as x approaches 2 from the left
1 as x approaches 2 from the right
indeterminate at 2

Answer 17

f of g = (x-5)^2-7(x-5)
x^2-10x+25-7x+35
x^2-17x+60

Answer 18

wow you were right with all. thanks very much