Physics - November 2006

U(r) = A [ [e^((R-r)/s) - 1]^2 - 1]

with r=distance between two atoms
and A, R, s are positive constants with s<
Find the equilibrium separation R0 at which U(R) is minimum.

2006-11-29 05:34:12 · 2 answers · asked by eeje2003 1

A particular engine has a power output of 5.00 kW and an efficiency of 20.0%. Assume the engine expels 6000 J of energy in each cycle.
(a) Find the energy absorbed in each cycle.

Your answer differs from the correct answer by 10% to 100%. kJ
(b) Find the time required to complete each cycle.
s

2006-11-29 05:19:43 · 1 answers · asked by activegirl 1

A copper rod and an aluminum rod of equal diameter are joined end to end in good thermal contact. The temperature of the free end of the copper rod is held constant at 100°C, and that of the far end of the aluminum rod is held at 0°C. If the copper rod is 0.88 m long, what must be the length of the aluminum rod so that the temperature at the junction is 50°C?

2006-11-29 04:47:36 · 2 answers · asked by activegirl 1

Right, a mass is moving in SHM on the end of a spring. The question gives me the force constant of the spring, and the amplitude of the motion. Thats all the info it gives.

The question asks, what is the maximum K.E. of this system.

I'm a bit confused because I can't see a way around the problem without knowing either the mass, or the frequency of oscillation

Can anyone give me any pointers?

2006-11-29 04:43:56 · 4 answers · asked by kirdish 2

A 80.0 kg person climbs 14.0 meters up a vertical rope. How many (food) Calories are expended in a single climb up the rope? (1 food Calorie = 103 calories)

2006-11-29 04:22:21 · 2 answers · asked by activegirl 1

2006-11-29 04:19:28 · 2 answers · asked by Anonymous

2006-11-29 03:47:02 · 11 answers · asked by uk_duggy_uk 3

2006-11-29 03:42:21 · 4 answers · asked by Marcus B 1

Here is my topic on physics: Study the energy change as a tennis ball rebounds from different surfaces.

Methods that i though of: Calculating Coefficient of Restitution, Energy lost as it rebounds, Coefficient of Friction.

Any ideas on this topic.....please i really need help on it

thanks

2006-11-29 03:40:06 · 4 answers · asked by sourav_chatterjee1989 2

Cant think of the name of this contraption...Its like that game mousetrap but that series of actions has a name.

2006-11-29 03:18:51 · 5 answers · asked by System 2

What is the relation of force to energy? I seem to be having trouble processing this for some reason. The speed of light is a force itself, yes?

2006-11-29 03:09:57 · 6 answers · asked by __ 3

Okay I'm doing my physics homework and I can't get one of the answers to one of the questions which is....
The mass of earth can be calculated using the fact that the weight of an object (in newtons) is equal to the force of gravity between the object and the earth. Given that the radius of Earth is 6.4 x 10^6 m determine its mass.

I don't need people to calculate it out I just need explanation of what to do and what formula to use.....

2006-11-29 03:07:12 · 7 answers · asked by BigMike 1

What is the difference between sonar and ultrasonic waves? What's the frequency range of each of them?

2006-11-29 02:44:47 · 8 answers · asked by Honest 1

It always amazes me just how loud sound is to our ears, even when the door or window is closed. How can dropping a ball cause so much disturbance that it shakes all the air and then all the atoms in the door, into our ear and still sound so loud! It just doesn't make sense, or does it?

2006-11-29 02:43:59 · 15 answers · asked by Michael B 2

2006-11-29 02:10:35 · 2 answers · asked by red-poka-dot-joe-bird 1

2006-11-29 02:06:56 · 15 answers · asked by Anonymous

Quite often (on the news for example) you see people in crowds who fire their guns into the air in celebration. Presuming the guns they fire are loaded with bullets and not blanks, do the bullets that fall back to the earth ever injure or kill people, or is their decent slowed enough by gravity not to do harm?

2006-11-29 02:01:48 · 17 answers · asked by martin 1

2006-11-29 01:55:25 · 7 answers · asked by martin 1

my idea is water has more of a smooth surface,so light is
reflected in a uniform way,giving you a more exact
outline of an object. everything else also reflects but at all kinds
of crazy angles you cant see a coherent shape.
could any scientifically trained ppl verify this?

2006-11-29 01:24:13 · 3 answers · asked by enigma q 2

2006-11-29 00:51:52 · 10 answers · asked by SAMITSUBHRO B 1

2006-11-29 00:37:50 · 13 answers · asked by Anonymous

2006-11-29 00:28:37 · 13 answers · asked by Anonymous

-material through which electrons flow freely
-arrangement of a material's electrons
-potential of a battery with flowing current
-inverse(opposite) of electrical conduction

2006-11-29 00:21:31 · 6 answers · asked by kzk_js 1

You are given two buckets of the same size. You are asked to carry a bucket full of water. Which one would you choose?
a. A bucket with broad handle
b. A bucket with thin handle

Explain.

2006-11-28 23:43:54 · 5 answers · asked by Grace 1

2006-11-28 23:29:27 · 7 answers · asked by Anonymous

2006-11-28 23:24:02 · 9 answers · asked by Nagendra M 1

Please use algebra to explain and give me a solution. This is taken from the Idiots Guide to Physics. They say that the answer is x= v0 t +1/2 at squared. why?

2006-11-28 22:30:37 · 6 answers · asked by Microbiologist 2

2006-11-28 22:29:12 · 14 answers · asked by Anonymous

Is it a technology thing?.......I may sound stupid and I probably am but I would still like to know. Thank you

2006-11-28 21:16:59 · 21 answers · asked by mrharderson 4

2006-11-28 20:55:42 · 4 answers · asked by no__one 1