Physics - November 2007

Hey there,
Can anyone please answer these questions:

(1) Is velocity on an incline constant or variable?
(So my graph should be a straight line or a curve?)

(2) Is acceleration on an incline constant or variable?
(So my graph should be a straight line or a curve?)

Thank you very much.

2007-11-15 06:12:55 · 1 answers · asked by Anonymous

I am a little confused about just how it works with regard to current flow. As far as I know, current flows from the negative pole to the positive, because electrons are attracted to the positive source.

Looking at power lines, I know the voltage is "stepped down" from high voltage carrier lines, to substations, and stepped down again before it gets to a house. Every pole has a ground wire run into the earth, which is the negative. My question is, then isn't the truth that, since the ground is the negative end, that the electricity should be flowing in the opposite direction, and that the voltage is actually "stepped up"?

Also, the truth is that if you touch one wire and not the ground, you don't get zapped. If the current is coming from the ground, and not trying to get to the ground, why can we safely touch the bare ground wire on poles?

2007-11-15 06:06:40 · 5 answers · asked by messenger_of_the_void 2

2007-11-15 06:06:01 · 5 answers · asked by Alexander 6

2007-11-15 05:59:43 · 7 answers · asked by Anonymous

4. In a tug-of war between the teams A and B, the rope breaks at a point which is nearer to A. Then
Answer : A has applied more force.

Please explain the answer.

Thanks.

2007-11-15 05:45:59 · 1 answers · asked by Prashant Kumar 1

If a cannonball is fired from a tall mountain, gravity changes its speed all along its trajectory. But if it is fired fast enough to go into circular orbit, gravity does not change its speed at all. Why?

2007-11-15 05:45:24 · 5 answers · asked by Anonymous

1. A stone S is tied to the middle of a string and suspended from one end O. If you give a sharp jerk at P, the other end of the string, then the string will break
Answer : below the stone

2. In the above problem, if we increase the pull at P gradually, the string will break
Answer : above the stone

Please explain the answers. It has got something to do with inertia.

Thanks.

2007-11-15 05:44:43 · 2 answers · asked by Prashant Kumar 1

Why does the force of gravity do no work on a satellite in circular orbit, but does do work on a satellite in elliptical orbit?

2007-11-15 05:44:25 · 3 answers · asked by Anonymous

2007-11-15 05:24:09 · 2 answers · asked by Anonymous

A disk-shaped merry-go-round of radius 2.58 m and mass 157 kg rotates freely with an angular speed of 0.596 rev/s. A 70.1 kg person running tangential to the rim of the merry-go-round at 3.31 m/s jumps onto its rim and holds on. Before jumping on the merry-go-round, the person was moving in the same direction as the merry-go-round's rim. What is the final angular speed of the merry-go-round?
rad/s

2007-11-15 05:17:05 · 3 answers · asked by Amber G 2

A uniform meter stick of mass M has an empty paint can of mass m hanging from one end. The meter stick and the can balance at a point 21.5 cm from the end of the stick where the can is attached. When the balanced stick-can system is suspended from a scale, the reading on the scale is 2.40 N. Calculate the mass of the meter stick.

2007-11-15 05:11:52 · 1 answers · asked by Anonymous

A crate rests on a flatbed truck which is initially traveling at 13.7 m/s on a level road. The driver applies the brakes and the truck is brought to a halt in a distance of 36.2 m. If the deceleration of the truck is constant, what is the minimum coefficient of friction between the crate and the truck that is required to keep the crate from sliding?

2007-11-15 05:09:37 · 1 answers · asked by jULIAN C 2

the crests of the waves causing the motion are 20 m apart
dtermine
the frequency of the wave
the speed of the wave

2007-11-15 05:03:02 · 3 answers · asked by John S 1

dtermine the wavelength of the wave

2007-11-15 04:59:58 · 1 answers · asked by John S 1

what is the frequency of the wave

2007-11-15 04:56:53 · 1 answers · asked by John S 1

we see in EM spectrum, microwaves on one side and x rays on the other side of visible light. Both x rays and micro waves are harmful for humans why visible light is not harmful for us.

2007-11-15 04:56:49 · 2 answers · asked by Kasprov 1

I know that it sends a beam of electrons down that bounce off and around an image, but how is the image then created?

2007-11-15 03:39:44 · 5 answers · asked by theburghguy 1

2007-11-15 03:27:56 · 7 answers · asked by Josh W 1

A lunch tray is being held in one hand, as the drawing illustrates. The mass of the tray itself is 0.200 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00 kg plate of food and a 0.275 kg cup of coffee. Obtain the force T exerted by the thumb and the force F exerted by the four fingers. Both forces act perpendicular to the tray, which is being held parallel to the ground.
T = N (downward)?
F = N (upward) ? link to image:http://img251.imageshack.us/my.php?image=0968lr6.gif

2007-11-15 02:59:56 · 2 answers · asked by Cameron 2

why is time going faster? is there another theory beside the "as we get older time appears to go faster"?

2007-11-15 02:04:15 · 4 answers · asked by Honesty 2

2007-11-15 01:46:42 · 8 answers · asked by yAng 1

...because an extrapolation loses contact with the objective reality the original theory was formulated to describe.

2007-11-15 01:41:05 · 3 answers · asked by mesun1408 6

2007-11-15 01:00:25 · 1 answers · asked by hullygully 1

1. what will the kinetic energy of an arrow having a potential energy of 50 J after it is shot from a bow?

also.

2. a boulder is raised above the ground so that its potential energy relative to the ground is 200 J. Then it is dropped. What is its kinetic energy just before it hits the ground?

thanks so much

2007-11-14 23:51:17 · 1 answers · asked by Anonymous

2007-11-14 23:21:50 · 2 answers · asked by Anonymous

2007-11-14 23:08:42 · 2 answers · asked by shin 1

A cylindrical water tank 1.5 m high is filled with water

a) find the pressure at the bottom of the tank

b) if the cross-sectional are of the tank is 4m2. find the total force at the bottom.

2007-11-14 22:49:33 · 1 answers · asked by kC 2

I believe it starts with the letter "Q".

And an example of what I am writing about is, when a ice cube is solid, but it is unstable because it can melt. And the flip side is, when the ice cube melts, it is no longer solid, but it is now stable.

Another example, is a clean bedroom, solid when clean, but unstable, because it can get messy. When messy, not solid, but stable.

2007-11-14 15:21:59 · 3 answers · asked by prc85040 3

Is there any formula in the world that related amplitude and frequency? Google and everything just completely failed me.

"Theoretically, if the amplitude of a mass-and-spring system is increased by a factor of 3, then the frequency will increase by a factor of:" Yet I have no idea how to figure it out.

2007-11-14 14:58:51 · 2 answers · asked by phrozenwarrior 3

I need help with my study on waves.

Can somebody give me some examples of energy transfers by waves and their sources? Preferably like 5 or so because I am kind of a slow student and the more I can try to understand the better.

2007-11-14 14:51:07 · 1 answers · asked by Detroit Needs Help 2