Physics - March 2007

Assume my equipment and I have a combined mass of 115 kg. And I go for a hike starting at Yosemite Valley (elevation = 1219 meters) and I walk up to the top of Half Dome (elevation = 2694 meters). What is my change in gravitational potential energy? If this hike-climb takes 7 hours, what is my average power output?

2007-03-12 09:24:53 · 1 answers · asked by GSU 1

2007-03-12 09:14:17 · 6 answers · asked by scott m 1

in a particular diode the current triples when the applied potential difference is doubled. what can you conclude about the diode?

2007-03-12 09:11:53 · 2 answers · asked by socom_lover 2

I know that light or fire is not a gas, liquid or solid so what the hell is it.. i believe that it may be plasma, but is that not only contained in space?
i will be very gratefull for any answers.

2007-03-12 08:55:57 · 12 answers · asked by Gupert 1

A barge of mass 5.0 104 kg is pulled along the Erie Canal by two mules, walking along towpaths parallel to the canal on either side of it. The ropes harnessed to the mules make angles of 45° to the canal. Each mule is pulling on its rope with a force of 1.0 kN. How much work is done on the barge by both of these mules together as they pull the barge 150 m along the canal?

2007-03-12 08:48:37 · 3 answers · asked by Anonymous

Thanks in advance for the help.

2007-03-12 08:33:38 · 2 answers · asked by theweirdguy1 2

Maybe you can give an internet site address that can be useful for this topic. But i want scientific answers.

2007-03-12 08:30:18 · 4 answers · asked by sabanguvenc 1

Two thin rectangular sheets (0.33 m 0.47 m) are identical. In the first sheet the axis of rotation lies along the 0.33 m side, and in the second it lies along the 0.47 m side. The same torque is applied to each sheet. The first sheet, starting from rest, reaches its final angular velocity in 7.0 s. How long does it take for the second sheet, starting from rest, to reach the same angular velocity?

2007-03-12 08:17:07 · 1 answers · asked by dawgs1918 1

a childs pogo stick stores energy in a spring with spring constant 21800 N/M. at position A(x1=-.06m) the spring compression is a maximum and the child is momentarily at rest. at position B ( x=0 m) the spring is relaxed and the child is moving upward. at position C (x2= height) the spring is still relaxed and the child is again momentarly at rest at the top of the jump. the acceleration of gravity is 9.8 m/s^2. mass of child and spring = 29 kg. at position C determine the height ?at position B calculate the speed of the child at x=0 ? determine the magnitude of x for which the kinetic energy of the system is at a max ?

2007-03-12 08:14:22 · 1 answers · asked by Anonymous

ok this is alot of numbers and information so here go
a lunch tray is being held by one hand. teh mass of the tray is .220 kg... its center gravity is at its center. on the tray is a 1 kg plate and a a .335 kg cup of coffee. obtain force t (exerted down ) by thumb and force f (exerted up ) by four fingers. both forces act perpendic. to tray, which is held parrallel to ground.. ...
other info....
length of tray is .400m
length from beginning of tray to .......
cup is .380m
plate is .240 m
four fingers is .100m
to thumb is .0600m

ok i tried settin up net force = 0 and net torque =0 then solving for the different components and things... someone i keep getting the wrong answer though... i dont know if i am messing up the formulas or if i am just missing something?!?!?! i know torque is force time lever arm so i dont know where i am going wrong could someone walk me through this so maybe i can see my mistake it would be great help it could just be a small error thank you

2007-03-12 08:13:13 · 1 answers · asked by Anonymous

2007-03-12 07:57:34 · 5 answers · asked by james p 1

Are there some conditions that need to be satisfied on the boundary , what does it mean , plz xplain in detail

2007-03-12 07:46:52 · 1 answers · asked by Devil 4

An isolated planet has orbital period T = 2 hours
for low circular orbits.

A body initially located at distance equal to 2 radii of the planet
from the center of the planet is released with zero initial speed.

How much time does it take for the body
to reach the surface of the planet?

2007-03-12 07:43:34 · 2 answers · asked by Alexander 6

What is the average cost of a 13 watt fluorescent light and a 60 watt incandescent light in canada and how much do you save every year if you use a fluorescent light(average)?

2007-03-12 07:40:07 · 1 answers · asked by wahoo 1

Wouldn't we already have it?

2007-03-12 07:38:04 · 8 answers · asked by Anonymous

What should i need to keep constant during my course work B.

2007-03-12 07:36:29 · 6 answers · asked by Anonymous

A 920 N crate rests on the floor.
(a) How much work is required to move it at constant speed 6.6 m along the floor against a friction force of 180 N?
J
(b) How much work is required to move it at constant speed 6.6 m vertically?
J

2007-03-12 07:32:00 · 3 answers · asked by nafiseh g 1

What is the minimum work needed to push a 1200 kg car 370 m up along a 17.5° incline?
(a) Ignore friction.
J
(b) Assume the effective coefficient of friction retarding the car is 0.25?
J

2007-03-12 07:30:29 · 2 answers · asked by nafiseh g 1

a)red light is refracted the most,while violet light is refracted the least
b)longer wavelengths are bent more than shorter wavelengths
c)each wavelength of light has it's own index of refraction
d)it polarizes the different wavelengths of light

2)the frequency of radiation is
a)directly proportional to it's wavelength
b)inversely porportional to it's velocity
c)independent of the temperature of the source
d)none of these

3)the quantum mechanical model of the atom differs from the bohr model in that it
a)considers the electron as a particle
b)considers the electron as a wave
c)predicts the specific location of the electron in an atom
d)states that electrons can only exist at specific distances from the nucleus

4)photons of which of the following colors of light posses the greatest amount of energy?
a)blue b)green c)yellow d)red

5)the maximum # of electrons that can have the principal quantum # 2 in a given atom is
a) 2 b) 4 c) 8 d) it varies from atom to atom

2007-03-12 07:22:43 · 4 answers · asked by Stacey lynn 2

2007-03-12 07:22:09 · 4 answers · asked by Anonymous

Is what i would like to see.Barring that,someone could explain why faster than light is impossible in such a way that can be easily understood.wouldnt the gravitational force of a black hole be "ftl"? Didnt the big bang expand the universe at ftl speeds?I guess i just dont like absolute rules.I hope that perhaps oneday ,this law will fall.

2007-03-12 07:20:52 · 6 answers · asked by Anonymous

2007-03-12 07:17:04 · 8 answers · asked by Voight-Kampff 3

2007-03-12 06:50:35 · 15 answers · asked by Pam B 1

I don't understand what is meant by a "matter wave." From what I understand, a wavefunction has to do with the probability of a particle being located at a certain position between a certain interval of time. Are they the same thing or is matter actually "waving" somehow?

2007-03-12 06:45:02 · 1 answers · asked by the redcuber 6

a movie stuntwoman drops from a copter that is 30m above the ground and moving with a constant velocity whose components are 10m/s upward and 15m/s horizontal and toward the south. a) where on the ground(relative to the position of the helicopter when she drops) should the stuntwoman have placed the foam mats that break her fall? draw x-t, y-t, Vxt, and Vyt graphs of the motion.

2007-03-12 06:29:18 · 1 answers · asked by smiley25 2

2007-03-12 06:23:55 · 5 answers · asked by mannjes62 2

A beam of light in air strikes a slab of crown glass (n=1.52) and is partially reflected and partially refracted.

2007-03-12 06:23:08 · 2 answers · asked by Anonymous

If particles behave as waves at times, what would the waves look like in 2D/3D? Is it even possible to visualize them at all?

2007-03-12 06:19:41 · 3 answers · asked by the redcuber 6

magnitude of the force required when the force applied at 53 degree to the wrench?

2007-03-12 05:59:32 · 1 answers · asked by Varun S 1

2007-03-12 05:56:15 · 4 answers · asked by GODLISTEN A 1