Mathematics - 4 October 2007

a motor is rated at 2238W and is 93% efficient . how much power must be supplied to the motor?

2007-10-04 07:02:59 · 3 answers · asked by slim8880 1

a) 1/24
b) 1/12
c) 1/8
d) 1/9
e) 2/9

2007-10-04 06:58:59 · 12 answers · asked by Smoothann 2

I have a sonic mouse repeller that says:

120v- 60Hz 12A. max

How many watts will it use each hour? Or each year?

2007-10-04 06:58:18 · 4 answers · asked by Anonymous

Please help . have maths h/w and i have to calculatre means on numbers

2007-10-04 06:54:21 · 9 answers · asked by Anonymous

I am trying to figure something out, but for some reason I keep hitting a brick wall. Any help would be VERY much appreciated!

I'm working on a spreadsheet right now for a fundraising thing. And basically, I need to know if there is any way to simplify what I'm trying to do.

With factorials, you're dealing with the PRODUCT of an integer and all the non-negative integers less than it. What I need to know is if there is any way to express the SUM of the integers. Like 5+4+3+2+1=15.

If that makes any sense at all, I'd appreciate any help. Thanks!

2007-10-04 06:50:46 · 5 answers · asked by Anonymous

find a cubic polynomial function f that satisfies the given conditions

rational zero 1/2, irrational zeros 1 + sqr(3) and 1 - sqr(3), coefficient of x is 2

*sqr = square root*

Answer: 2 ( x - 1 - sqr(3)) (x - 1 + sqr(3)) (x - (1/2)) ??

thanks for your help

2007-10-04 06:47:58 · 2 answers · asked by Oliver 2

At a fourth of July celebration, a rocket is launched with an initial velocity of 125 feet per second. The height (h) of the rocket in feet above sea level is modeled by the formula h=125t-16t(squared), where t is the time in seconds after the rocket is launched.

a. What is the height of the rocket when it returns to the ground?
b. how many seconds is the rocket in the air before it returns to the ground?
c. About how high does the rocket actually reach?

2007-10-04 06:37:24 · 4 answers · asked by taylor_travers098 2

One wheel turns 33 1/3 revolutions per minute. A second wheel turns at 45 revolutions per minute. At some point,a mark on each wheel is at the lowest point on each wheel at the same time. What is the least number of seconds until the marks on both wheels are again at the lowest point at the same time?

2007-10-04 06:11:46 · 2 answers · asked by henri b 1

How do you calculate gas flow through a volume

2007-10-04 06:10:02 · 1 answers · asked by nathaniel49 2

A student forgot the Product Rule for differentiation and made the mistake of
thinking that (fg)' = f'g'. However, they were lucky and got the correct answer.
The function f that they used was f(x) = e^(x^2) and the domain of the problem was
the interval ( 1/2 , infinity). What was the function g?

2007-10-04 06:01:03 · 3 answers · asked by Anonymous

y=3u^2+2u, u=4x

2007-10-04 05:53:39 · 6 answers · asked by clove88 2

Note* the letters DO NOT eqaul their postion in the numeric alphabet. The letters DO NOT correspond with Rozing's Santax Multiplication of Alphabets

If A and Y equal H.
And twice B plus half of Y equal U.
And L times V minus W is A.
And A is greater then the product of L times 2 plus B, (U), X, M, V, F or (T).

T + U + ___ = (-) [W]

2007-10-04 05:47:46 · 3 answers · asked by joie_333 2

What is the cross product of the cross product of the dot product of the vectors a = <3,4,5> and b = <5, 6, 7>?

What does it geometrically mean?

2007-10-04 05:46:03 · 4 answers · asked by Axis Flip 3

2007-10-04 05:32:52 · 2 answers · asked by damasta_007 1

The differnece of twice a number and 16
is equal to the quotient of three times the number and 8


never really understood it please help

2007-10-04 05:24:55 · 5 answers · asked by Yesenia 1

two people standing 10 feet apart are holding opposite ends of a jump rope. The height of the jump rope x feet from the person on left is given by:
h(x,t)=3+3sin ((pi/10)*x) cos(2pi*t)

give a practical interpretation of each of the following quantities:
a) h(5,2)-h(0,2)
b) h(5,2)-h(5,0)

2007-10-04 05:22:54 · 1 answers · asked by Nomad 1

can you solve:
y=7x-9
y=x^2 + 1

thank you

p.s. can you show how it was done?

2007-10-04 05:14:01 · 8 answers · asked by Twista-Adzy 2

whats geometry??

2007-10-04 05:08:25 · 5 answers · asked by Anonymous

Solve for w(t) at t=100s if dw/dt = 0.025 s^(-1) w + 75
if w(0)=2.75.

0.025 s^(-1) is a constant coefficient in front of w.


I need to show all work, and don't understrand Diferentaion and inergrals too well...so if you can solve this showing a step by step way to follow that will be greatly appreciated.

2007-10-04 05:02:01 · 1 answers · asked by j2dabizo 1

2007-10-04 04:59:12 · 5 answers · asked by g_jo8 2

how would i know this this rule applies?

i know it does to many functions. but could someone explain to me why this is?

thank you guys

2007-10-04 04:57:04 · 5 answers · asked by blank 2

How would you go about solving this problem?
(IDK how to solve because there are 2 variables. The height and the second base.
A 10 ft sectionis of gutter is made from a 12 in wide strip of sheet metal by folding up 4 in strips on each side so that they make the same angle with the bottom of the gutter. Determine the depth of the gutter that has the greatest carrying capacity

2007-10-04 04:53:43 · 1 answers · asked by Frank C 1

I'm not so good with word problems, for someone reason I always get confuse with the numbers and words and if I really need it or not. So here it is:

Jim Olsen makes and sells gourmet food items. He makes two types of salad dressings: garlic and tofu. Each gallon of garlic dressing requires 2 qt. of oil and 2 qt. vinegar. Each gallon of tofu dressing requires 3 qt. of oil and 1 qt of vinegar. Jim makes $3 profit on each gallon of garlic dressing and a $2 profit on each gallon of tofu dressing. He has 18 qt of oil and 10 qt of vinegar on hand. How many gallons of each type of dressing should he make to maximize his profits?

If you know a website that can help me that would be nice.

2007-10-04 04:50:15 · 3 answers · asked by Anonymous

1. 7(3c-2d)-5(2c-3d)
2. 3(m-n)-3(m+n)
3. 3(r+2s)-(r+s)
4. 2(3p-2q)-3(2q-7q)
5. 2(3x-5y)-3(2x-y)
6. 4(3g+2h)-(5g-2h)
7. 4(3a-4b)-3(2a+5b)
8. 7(2x+y)-5(x-2y)
9. 3(2c-3d)-3(3c-2d)
10. (3m-7n)-(2m+3n)
11. (6w-3y)-(3w-4y)
12. 3(3x+2y)-4(3x-4y)
13. 4(3x-4y)-(2x-7y)
14. x(3x-2y)+y(3x-4y)
15. a(3a-4b)+2a(a-b)

2007-10-04 04:42:55 · 4 answers · asked by Alicia ... 2

the sum as i goes from 1 to n of (n x n+1) = n(n+1)(n+2)/3
this is just so confusing!! every time i think i have it figured out i get so lost. any help would be great. 10 points to whoever completes the entire proof.
thanks for all your help

2007-10-04 04:41:42 · 3 answers · asked by numbr1TXfan 4

i asked this question earlier but i still didnt understand , so i need some one to really break it down for me with ..some word details towards every step. please :(

2007-10-04 04:33:10 · 5 answers · asked by Anonymous

2007-10-04 04:28:34 · 1 answers · asked by RogerDodger 1

what is the second derivative test? how can you test for concavity? how can you find relative extrema using second derivative test? how can you find points of inflection? how do you know when a function increases or decreases?

2007-10-04 04:21:16 · 2 answers · asked by Sheee-Luh-Gee 1

2007-10-04 04:17:46 · 6 answers · asked by nathan 2

For example, if I want to calculate 2^0.6 without a calculator, how can I do this? I just came to the realization that I've been in school for a long time without ever finding this out! (They're about to give me a bachelor's in mechanical engineering for crying out loud!) A good link would be just as helpful as a long-winded explanation. Thanks.

2007-10-04 04:09:18 · 0 answers · asked by kevinthenerd 3