Science & Mathematics - 3 November 2007

i have to write a physics investigation and I am greatly struggling, i have to write an aim, the variables.a hypotheis, method etc but its been a long time since i did the experiment so need a little help with understanding the physics behind the experiment, the title is:

to investigate how the force acting on a wire, due to a magnetic field, depends on the current flowing in the wire.

To do the experiment we made a u shaped magnet by placing the two magnadur magnets on the steel yoke with opposite poles facing each oter

we placed the magnet on the top-pan balnce to read 0

we arrange a stiff copper wire to pass centraly between the poles of the magnet

we assembled a circuit to provide a variable

i gathered some results and found the reading on the balance to go up when the current goes up ? why?? is this?? anyone got any help or advice?

2007-11-03 23:58:07 · 5 answers · asked by Anonymous in Physics

Trace metals in geochemistry is defined as 'all elements except the eight abundant rock-forming elements: oxygen, silicon, iron, calcium, potassium, and magnesium'

2007-11-03 23:57:58 · 1 answers · asked by Anonymous in Chemistry

Please point me to books / sites where I can learn more about the practical uses and little-known 'secrets'.

2007-11-03 23:56:41 · 6 answers · asked by Megan 3 in Paranormal Phenomena

how do i convert (-135 degrees) to radians using a calculator?

2007-11-03 23:53:46 · 4 answers · asked by SeXxY&SmArT 2 in Mathematics

A speedboat increases its speed from 50 ms-1 to 80 ms-1 in a distance of 200 m.
What is the the magnitude of its acceleration?
the time it takes the boat to travel this distance?
i am totally lost on my physics homework..
can some scientist help me out.. and show me the formulas /steps used to solve? thx

2007-11-03 23:50:32 · 3 answers · asked by BoBomakeup 2 in Physics

Since longitudinal lines are like "markers" for time, (every 15 degrees is one hour) and all longitudinal lines meet at the North Pole and South Pole, what time is it at the exact point that these lines meet?

Or even the North or South pole?


And if you were to stand a meter away from the point of convergence and run around it in a circle, wouldn't that be considered traveling time???

Heheheh...:D

2007-11-03 23:29:47 · 3 answers · asked by 11 4 in Physics

Do you think they are?

2007-11-03 23:22:36 · 12 answers · asked by Anonymous in Zoology

The electric motor of a model train accelerates the train from rest to 0.580 m/s in 20.0 s. The total mass of the train is 875 g. Find the average power delivered to the train during its acceleration.

i know you use average power=work over change in time, but how to find work?

2007-11-03 23:16:13 · 0 answers · asked by AmandaLiu 1 in Physics

2007-11-03 23:12:29 · 19 answers · asked by Anonymous in Earth Sciences & Geology

1. some people used to think that a rocket could not travel to the moon because it would have no air to push aginst once it left the earths atmosphere. we now know that idea was mistaken. what force propels a rocket when it is in a vacuum?

2. since the force that acts on a bullet when a gun is fired is equal and opposite to the force that acts on the gun, does this imply a zero net force and therefore the impossibility of an accleration bullet?

3. suppose you exert 200N on your refrigerator and push it across the kitchen floor at constant velocity. what friction force acts between the refrigerator and the floor? is the friction force equal and opposite to ur 200N push? does the friction force make up the reaction force to your push?

2007-11-03 23:03:52 · 2 answers · asked by Anonymous in Physics

1. your weight is the result of the gravitational force of the earth on your body. what is the corresponding reaction force?

2. when a high jumper leaves the ground, what is the source of the upward force that accelerates her? what force acts after her feet are no longer in contact with the ground?

3. If action equals reaction, why isnt the earth pulled into orbvit around ac ommunications satellite?

4. a speeding bus makes contact with a bug that splatters onto the windshield. because of the sudden force, the unfortunate bug undergoes a sudden deceleration. is the corresponding force that the bug exerts against the wind-shield greater, less, or the same? is the resulting deceleration of the bus greater than, less than , or the same as that of bug?

please explain how to do these. thanks!!!!!

2007-11-03 22:57:30 · 1 answers · asked by Anonymous in Physics

2007-11-03 22:48:18 · 1 answers · asked by Joel D. 2 in Physics

2007-11-03 22:40:33 · 6 answers · asked by MaryJOy G 1 in Chemistry

2007-11-03 22:35:04 · 5 answers · asked by the truht 2 in Zoology

Funny kind of a stinging feeling, isn't it? Not like a beesting at all, but it sticks around a lot longer- months afterwards I could still see a venemous residue beneath the skin, though the pain was gone by then. What sort of venom do they have, should it be treated with acid or alkali?

2007-11-03 22:34:08 · 9 answers · asked by Buzzard 7 in Zoology

This experemet called Iodoform Test for identification of carbonyl group.
Please when you answer my question tell me your Referance (Source) it is very important

2007-11-03 22:33:12 · 2 answers · asked by King of the Kings 1 in Chemistry

fuzziness or movement? sorry if it sounds stupid, its a serious question

2007-11-03 22:24:51 · 4 answers · asked by confused 1 in Physics

i know its mass*velocity/speed.

but lyk...what's so important about momentum and why do we need to know it?
also, is there an equation for impact?

2007-11-03 22:12:23 · 4 answers · asked by Anonymous in Physics

In the corner of our bathroom window we have a ladybird nest. They are red with black spots but we are wondering if they can do any harm and if they will just die out on their own now that it is winter.

2007-11-03 22:12:04 · 4 answers · asked by mememe 2 in Zoology

2007-11-03 21:58:00 · 7 answers · asked by Alex 1 in Botany

Then, dx/dt = -3/t^2.

The integral of 1/(9+x^2) dx = the integral of (-3/t^2)/(9+(3/t)^2) dt = (-1/3)*the integral of 1/(1+t^2) dt = (-1/3)*arctan(t) + C = (-1/3)*arctan(3/x) + C.

I know we can just derive the integral using the formula for the derivative of tangent inverse. But will this substitution work? Is it correct?

Thanks!

2007-11-03 21:53:39 · 2 answers · asked by Anonymous in Mathematics

What is the best ghost hunting site?

WWW.USAGHOSTHUNTERS.COM
i heard is the best to find your local ghost hunting groups.

2007-11-03 21:51:48 · 9 answers · asked by Anonymous in Paranormal Phenomena

" Briefly explain the concept of steady state as it applies to

diffusion."

Please help me!!

Thanks a lot!!!

2007-11-03 21:50:08 · 2 answers · asked by michaelfnck 3 in Engineering

what is the easy way or technique in proving trigonometric identities?
ex. 1-cos/1-sin=tan

2007-11-03 21:49:40 · 5 answers · asked by Anonymous in Mathematics

12 balls of equal weight except one are given to u with a balance. find the weight of the differing ball by using the balance scale. you can use the balance scale only for 3 times. You will have to also the ball which is different in weight form others is lighter or heavier. please answer

2007-11-03 21:47:05 · 2 answers · asked by abdul n 1 in Physics

2007-11-03 21:45:22 · 2 answers · asked by Anonymous in Chemistry

and why is it that instead of helping countrys where they are dying from poverty and disease, nasa spends billions of dollars on going to space? this makes me angry considering, how many of us are really going to go to space?

2007-11-03 21:45:09 · 7 answers · asked by emesumau 4 in Astronomy & Space

day light savings

2007-11-03 21:39:39 · 7 answers · asked by Anonymous in Earth Sciences & Geology

the remaining 1 question has 5 possible answers. What will be the total number of possible answers?

2007-11-03 21:37:37 · 5 answers · asked by raj 7 in Mathematics

This is the question:

NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large,
low mass sail and the energy-momentum of sunlight for propulsion.
(a) Should the sail be absorbing or reflective?
(b) The total power output of the sun is 3.9x1026 W. How large a sail is nececary to propel a
10,000 kg spacecraft against the gravitational force of the sun? Express your result in square
kilometers.
(c) Explain why your answer to part (b) is independent of the distance from the sun?

You will need to use F=GMm/r^2 as the expression for gravitational force.

How to do it!!!

Btw, the answer to (a) is reflective.

2007-11-03 21:36:37 · 1 answers · asked by Anonymous in Physics