Science & Mathematics - 1 November 2007

2007-11-01 20:42:02 · 3 answers · asked by Richard D 1 in Astronomy & Space

A man with mass 70.0 kg stands on a platform with mass 25.0 kg. He pulls on the free end of a rope that runs over a pulley on the ceiling and has its other end fastened to the platform. The mass of the rope and the mass of the pulley can be neglected, and the pulley is frictionless. The rope is vertical on either side of the pulley.

Question: What is the acceleration of the rope relative to him?

the platform has an upward acceleration of 1.8 m/s
And I have found the force he needs to pull is 551N

2007-11-01 20:28:29 · 2 answers · asked by Potato Monster 2 in Physics

2007-11-01 20:25:51 · 4 answers · asked by Richard D 1 in Astronomy & Space

I don't remember how to calculate the percent?
for example,I want to buy something that cost 130 dollars,and there is a 20% of discount?how can I calculate the final amount?or vice versa..

2007-11-01 20:21:14 · 30 answers · asked by Anonymous in Mathematics

prime and composite

2007-11-01 20:20:06 · 26 answers · asked by dennis f 1 in Mathematics

Find the initial velocity of the rocket shooting up at 150 feet. (Assuming it went up straight) Find the time it takes to go up.

THis is my last problem and i am stuck please help!

2007-11-01 20:19:49 · 5 answers · asked by Michael 2 in Physics

How do we integrate tan(x)*Sec(x). Would it be by substitution, letting u = tanx?

2007-11-01 20:11:48 · 7 answers · asked by chengdu 1 in Mathematics

For example 9x+10=7x-6 do i
9x+7x=-6+10 or
9x-7x=-6-10?

I don't know when to subtract or add

Please help

2007-11-01 20:06:38 · 10 answers · asked by Anonymous in Mathematics

the function is a piecewise function:

F(r) =
{ (mgR^2) / r^2 if r >= R
{ mkr if 0 <= r < R

g and k are positive constants and R is the radius of the earth. given that F(r) is continuous, find k in terms of g and R...

no idea where to start...

2007-11-01 19:56:17 · 2 answers · asked by Anonymous in Mathematics

Mount everest is in northern part of Nepal.

2007-11-01 19:52:39 · 5 answers · asked by Deepak B 1 in Geography

2007-11-01 19:51:57 · 0 answers · asked by ALEXANDER 2 in Mathematics

2007-11-01 19:44:12 · 4 answers · asked by chillywi11y 2 in Earth Sciences & Geology

2007-11-01 19:43:03 · 8 answers · asked by jennifer h 1 in Biology

You can use a calculator, i assure you its not what you would expect....or is it?

2007-11-01 19:40:14 · 16 answers · asked by *Smokers* 1 in Mathematics

Hari wants to set up a 1500m obstacle course.
The start-finish line is at grid reference 251132. The first leg is 600m long. First turn is at grid reference 631596. Second leg is 250m long at a bearing of 309 degrees.
Is this a 1500metre course?

2007-11-01 19:34:03 · 5 answers · asked by Trev M 1 in Mathematics

2
(x1-1)( x + 3x + 2)

(one x take away one)(x to the second power plus three x plus 2)


he wants us to multiply

2007-11-01 19:31:59 · 7 answers · asked by Amy4U 1 in Mathematics

2007-11-01 19:31:06 · 7 answers · asked by bakanka1@yahoo.com g 1 in Biology

2007-11-01 19:26:25 · 5 answers · asked by bakanka1@yahoo.com g 1 in Botany

What happens to energy as it is transformed?

2007-11-01 19:25:56 · 3 answers · asked by Anonymous in Biology

overtake kart XJ,however kart XJ then accelerates at a constant of 0.25mph each second until it passes ZX. How long will ZX be ahead XJ?

Been having trouble solving this one,please show in as detailed as possible. Thankx for the help everyone.

2007-11-01 19:24:28 · 3 answers · asked by Luv Dual-Core 2 in Physics

when u minus two numbers the answer u get is 8 .. wen u multiply its 17 so what will u get wen sum of their squares is taken.

It's meant to be very easy.

2007-11-01 19:23:32 · 2 answers · asked by Jenny H 2 in Mathematics

With changing climate awaiting us, and world food supplies at risk, aren't drought resistant, pest resistant crops exactly what we need? Yes, yes, I know, they aren't proven safe. But what would be the relationship between genetic modification to increase production, and safety to the consumer. Isn't it like saying "crops produced using agricultural equipment that runs on hydrogen fuel aren't proven safe". I'm wondering if it is just political hype causes us to shoot ourselves in the foot. This is not an opinion, it's a question. I am listening..

2007-11-01 19:23:14 · 8 answers · asked by kwaaikat 5 in Biology

2
4n - 3n - 1
3n
___________



the 2 floating means to the second power

2007-11-01 19:21:56 · 7 answers · asked by Amy4U 1 in Mathematics

How could I solve this problem?

If (-4, 1) is an ordered pair of the function f(x), then which of the following would be an ordered pair of f ^-1(x)?

1) (1, -4)
2) (4, -1)
3) (4, 1)
4) (-1, 4)

2007-11-01 19:20:44 · 2 answers · asked by Anonymous in Mathematics

2007-11-01 19:18:27 · 1 answers · asked by kitkat 1 in Biology

Just for fun, I was doing a proof of propositional logic, but I got stuck trying to prove that Pv(QvR) implies (P&Q) v (P&R).

I tried assuming the negation of (P&Q) v (P&R) --in order to negate that later and get (P&Q) v (P&R)-- but it's not getting me anywhere... anyone know the answer?

2007-11-01 19:16:17 · 2 answers · asked by Flaze 3 in Mathematics

human males may suffer from having just one copy of the X chromosome, while females have two?

This part is really confusing to me so please answer and explain... Thank you!

2007-11-01 19:15:08 · 3 answers · asked by Hanna 2 in Biology

2007-11-01 19:14:32 · 19 answers · asked by peace 1 in Zoology

I live in San Jose, California and recently was struck with a 5.6 earthquake on October 30th.(The first large earthquake since the 1989 S.F. quake.) 96 aftershocks and mini-quakes has been recored since last week and after the initial earthquake.
The probability of "The Big One" striking is 10% within the next two weeks. I was wondering what would the Federal Government's and FEMA's response would be.

2007-11-01 19:14:25 · 2 answers · asked by ? 2 in Earth Sciences & Geology

2007-11-01 19:12:19 · 1 answers · asked by Krista J 2 in Chemistry