Physics - September 2007

It has been suggusted thaty rotating cylinders about 16 km and 8 km in diameter should be placed in space for future space colonies. The rotation would simulate gravity for the inhabitants of these colonies. Explain the concept behind this proposal.

2007-09-09 15:44:03 · 2 answers · asked by Oscar A 2

I really need help

2007-09-09 15:37:05 · 1 answers · asked by Anonymous

2007-09-09 15:31:16 · 3 answers · asked by 123 1

help me plzz

2007-09-09 14:59:13 · 3 answers · asked by its a secret 2

car B travels at a constant speed of 90 km/h. while car A accelerates uniformly 0 to 150 km/h , reaches top speed after 5x10^ -3 hours, then travels at a constant speed speed. what is the acceleration rate of car A and when will car A reach car B?

2007-09-09 14:21:09 · 1 answers · asked by Anonymous

we have this task from our teacher to design a container or some kind of device to protect a raw egg as it falls to the ground from the second storey of a building. the given materials are scotch tape, straws, and newspapers. you are allowed to use ONLY these materials. you CANNOT change the egg in any way (no tape on the egg, etc). please help me i'll give 10 points!!

2007-09-09 13:39:20 · 6 answers · asked by infernape 2

A 1.3-kg object is moving in the x direction at 15 m/s. Just 3.35 s later, it is moving at 28.2 m/s at 32.4° to the x axis. What are the magnitude and direction of the force applied during this time?

2007-09-09 13:31:04 · 2 answers · asked by Nathan R 1

A tennis ball with a speed of 12.7 m/s is thrown perpendicularly at a wall. After striking the wall, the ball rebounds in the opposite direction with a speed of 8 m/s. If the ball is in contact with the wall for 0.01s, what is the average acceleration of the ball while it is in contact with the wall? Answer in units of m/s.

2007-09-09 13:13:54 · 3 answers · asked by Anonymous

So... for a while I thought I had it all figured out. I decided that UV was within the visible spectrum, because florescent things glowed under black lights. I figured that they were all the same. But... they aren't. So now I'm completely confused. What is florescence, how does ultra violet light differ from the light emitted by black lights? Do both Ultra violet and blacklights make florescent things glow? I have a pretty good understanding about light, photons, and colors... but this is a rough spot. Shed some "light" on the subject please.

2007-09-09 13:09:40 · 1 answers · asked by notallchipsarefood 3

A car with a mass of 1300 kg is initially moving at a speed of 40 km/h when the brakes are applied and the car is brought to a stop in 15 m. Assuming that the force that stops the car is constant, find (a) the magnitude of that force and (b) the time required for the change in speed.

If the initial speed is doubled and the car experiences the same force during the braking, by what factors are (c) the stopping distance and (d) the stopping time multiplied? Show your work.

2007-09-09 12:38:18 · 3 answers · asked by Anonymous

What is the basic difference between a mathematician and a physicist considering they both deal with numbers?

2007-09-09 12:04:54 · 1 answers · asked by Anonymous

A car starts from rest and travels for 4.9 s with a uniform acceleration of +1.2 m/s(squared). The driver then applies the brakes, causing a uniform acceleration of -2.2 m/s(squared). The breaks are applied for 1.70 s.

2007-09-09 11:40:45 · 1 answers · asked by Steve Gaines 2

2007-09-09 11:37:56 · 8 answers · asked by james 1

What does this quote mean?

2007-09-09 11:31:40 · 1 answers · asked by xburned_icex 1

A parachutist descending at a speed of 9.40m/s loses a shoe at an altitude of 31.60m.

(a) What is the velocity of the shoe just before it hits the ground?

2007-09-09 11:14:20 · 3 answers · asked by Anonymous

You swing a 2.60kg stone in a circle, using the full length of a thin 80.0cm rope.
At what speed should you swing it so its acceleration will be 9.8 m/s^2 ?

2007-09-09 11:06:35 · 1 answers · asked by Anonymous

and one more two planes intersect in only one point? geometry
HELP!! true or false

2007-09-09 11:06:08 · 2 answers · asked by Anonymous

2007-09-09 11:04:23 · 7 answers · asked by Anonymous

Hello, I was watching a television show last night on mega black holes and the mystery around how they were created...They found balck holes in the center of every galaxy.

Nobody mentioned this on the show, but I am wondering, has anyone ever considered that they could have been created by the big bang for our galaxy, but big bangs for every galaxy....?

Here is why I am asking....If you look at what happens in a nuclear explosion, things get shot away, then they start recoiling back. Kind of like dropping a stone in the middle of a bowl, the wave eventually comes back to the center..

I know that there is something wrong with my thought because these physicist already looked at it as being a possibility and dismissed it.

Does anyone know why it is not plausibile?

2007-09-09 10:59:16 · 3 answers · asked by Art G 4

Canoeist 1 paddles with a speed of 1.35m/s at an angle of 45 degrees north of east. Canoeist 2 starts on the opposite shore a distance of 1.5km due east of the canoeist 1.
a) In what direction relative to North must canoeist 2 paddle to reach the island?
b) What speed must canoeist 2 have if the two canoes are to arrive at the island at the same time?

Could you please explain the steps to me, I couldn't find the equation for this question in my book?

2007-09-09 10:32:21 · 1 answers · asked by lorinkuuipo 1

How do scientists explore earlier times or places that they can't visit and observe directly?

Like the jurassic period and when the solar system was created??

2007-09-09 09:56:51 · 2 answers · asked by Anonymous

My son is doing a project on dropping objects. He needs to know what affects dropping objects and how.

2007-09-09 09:49:25 · 4 answers · asked by Lawrence O 2

I'm coming up with the wrong answer and I don't knwo why.

10.13 m/s= (3ft/1m)(1 mi/5280ft)(60s/1hr)
Meters, seconds, and feet cancel out leaving mph, but I'm getting something else.

2007-09-09 09:41:13 · 3 answers · asked by Anonymous

Ok, I've been working on this and I am stumped. I don't necessarily want the answer, but a point in the right direction:

A free falling object takes 1.50 s to travel the last 29.0 m before it hits the ground. From what height above the ground did it fall [no wind resistance]?

2007-09-09 09:01:10 · 4 answers · asked by hyped83 2

Runner A is initially 6.2 Km west of a flagpole and is running with a constant velocity of 4.0 km/h due east. Runner B is initally 2.4 km east of the flagpole and is running with a constant velocity of 2.0 km/h due west. What will be the distance of the two runners from the flagpole when their paths cross?

2007-09-09 08:24:57 · 4 answers · asked by Anonymous

length of rope is not known. you are having only the rope, a matchbox and a pair of scissors.

2007-09-09 08:23:22 · 2 answers · asked by Anonymous

2007-09-09 08:17:11 · 2 answers · asked by Seanyy 3

I am having trouble tackling this problem:
"A car makes a 60.0-km trip with an average velocity of 40.0 km/h in a direction due north. The trip consists of three parts. The car moves with a constant velocity of 25 km/h due north for the first 15 km and 62 km/h due north for the next 32 km. With what constant velocity (magnitude and direction) does the car travel for the last 13-km segment of the trip?"

Here's what I've done so far:
40 km/h =(25 km/h + 62 km/h + x) / 3

120 km/h = 25 km/h + 62 km/h +x

120 km/h = 87 km/h + x
33 km/h = x
^not even sure if thats the correct way to do it. any help will be highly appreciated!!!!!

2007-09-09 08:13:02 · 1 answers · asked by PodCaster 1

I have a 20cl full bottle of vodka with has "37.5% vol" on the label. how many grams of alcohol does the bottle have?

also,is 20cl = 20mlitres?

2007-09-09 08:07:56 · 2 answers · asked by cccc 1

I have a waterpik which is like an electric toothpick thing used to clean your teeth. well i accidentally dropped the end of the plug into the little bowl of water, but only for like 2 seconds then i immediately pulled it out and wiped it with a washcloth. if i tried to plug it in, and its been a day later, would i get electrocuted?

2007-09-09 08:06:00 · 5 answers · asked by sara 3