Mathematics - 21 September 2007

I need help with this problem. A rock is thrown straight up with an initial velocity of 48 feet per second from an initial height of 64 feet above the ground. Its height h at time t is given be the formula h(t)=-16t^2+48t+64

1. find the time when the rock hits the ground.
I got this one 4 seconds, right?

2. find the maximum height of the rock?
this is the tough one? what should i do to solve it?

2007-09-21 06:15:39 · 4 answers · asked by mikhailb89 1

How would I go about integrating this function:

sqrt(2/a) integral (0-->a) [sin (n*pi*x / (a))] / (sqrt (x)) dx

This is Integral of sin (n*pi*x/a) / sqrt(x)

It's kind of hard to explain? Sorry. I hope someone can help.

Love,
Mary

2007-09-21 06:04:03 · 7 answers · asked by ♥ Mary ♥ 3

I'm having a brain fart. I should REALLY remember how to do this, but I don't:

wz(sqrt 12w) + 2wz(sqrt 3w)

Thank you!

2007-09-21 05:43:00 · 8 answers · asked by chrizzle08 2

2007-09-21 05:36:13 · 11 answers · asked by nala 1

Do I have correct answers for these?

1.252 x .115 x .012 = .0017

(1.278 x 10 to the third) / (1.4267 x 10 to the second) = 8.958

505-450.25 = 54.3

Please help. I am so confused.

2007-09-21 05:29:57 · 6 answers · asked by patriciaannbee 2

2007-09-21 05:28:12 · 9 answers · asked by pedro i 1

rectangular shape

2007-09-21 05:26:54 · 7 answers · asked by karalyn b 1

If Maria hit 8 home runs in 15 softball games, then she should hit 24 home runs in 45 games.

2007-09-21 05:21:52 · 2 answers · asked by Anonymous

240 pounds of fertilizer/6 lawns

2007-09-21 05:19:46 · 4 answers · asked by Anonymous

The ratio 5 3/5 to 2 1/10

2007-09-21 05:15:16 · 4 answers · asked by Anonymous

The winner of an election for class president won by a vote of 8 to 5 with 992 votes. How many votes did the loser get?

2007-09-21 05:06:45 · 5 answers · asked by Anonymous

Please explain in simple, easy to understand terms for a stupid person like me.

2007-09-21 04:59:37 · 3 answers · asked by Bob 2

I need the exact steps and some helpful tips to solve this equation y+ 10=x for y. I hear that you gotta isolate the variable. What does that mean? I need exact steps please. I really appreciate all help. Thank you everyone

2007-09-21 04:57:11 · 5 answers · asked by Luvon 3

2007-09-21 04:45:51 · 4 answers · asked by Detroit Ciudad 2

the second of two numbers is 4 more than the first. The sum of the numbers is 56.
If x represents the first number, and y represents the second number, what are the numbers?

If you answer, can you show me HOW you got your answer?

2007-09-21 04:38:13 · 3 answers · asked by emzahlee 2

2007-09-21 04:19:45 · 9 answers · asked by Anonymous

a scateboarder rolls down a hill with the acceleration of 4.0m/s2(squared). he is on a hill for 4.8s (seconds). what is the change in his speed ?

m-meters s-seconds
explain in full detail formula

2007-09-21 04:18:53 · 5 answers · asked by Anonymous

two blocks: b1=3kg, b2=1kg;
frictionless surface; massless pully, massless cord
b1, in a flat surface, force --> = 2.3 N

__b1------------------O <--pulley.
_____________ __`_.
floor_ _____________`b2

b2 is at an angle of 30 degrees from floor to pulley

a) need tension of cord above,

Also, b) what is the biggest value the magnitude of F--> may have w/out the cord becoming slack.

notes: confused about where the Sine goes in the equation for part "a)"

2007-09-21 03:56:56 · 2 answers · asked by Ar J 2

Alright. I have to convert two decimal numbers into binary. And then add them together. Then I have to show that the sum of the binary numbers is = to the sum of the decimal numbers.

Ok the numbers are 257 & 431. Their sum is 688.

I am sooo close on this but for some reason I'm just one number off. Can you please help me???? PLEASE??

Also am I right in that 688= 1010110000?

THanks in advance.

2007-09-21 03:46:21 · 5 answers · asked by I Ain't Your Momma 5

2007-09-21 02:57:13 · 5 answers · asked by nickmydog 1

2007-09-21 02:56:41 · 4 answers · asked by nickmydog 1

2007-09-21 02:36:43 · 8 answers · asked by steve R 1

?

2007-09-21 02:36:10 · 4 answers · asked by Anonymous

what two numbers (not decimal or fractions, normal whole numbers) I have to divide to get pi?

I know you can get it by dividing perimeter with radius, but they are both calculated with pi. and I need 2 ordinary numbers to divide to get infinite pi.

pls help...

2007-09-21 02:11:38 · 11 answers · asked by ? 4

I need to write a 5-page paper on any topic I so choose on number theory and discrete mathematics. Any suggestions?

2007-09-21 02:09:28 · 2 answers · asked by Anonymous

I hate my math teacher- she wasnt suppose to give us homework on a Friday night


5 1/3 - 2 2/3

2007-09-21 01:47:19 · 9 answers · asked by MMM Ice Cream 1

3x + 6y = 0 x=2/3

2007-09-21 01:43:49 · 8 answers · asked by MMM Ice Cream 1

i have just started redoing my gcse

2007-09-21 00:29:49 · 5 answers · asked by michael b 1

2007-09-21 00:22:14 · 16 answers · asked by tuga862002 1