Physics - March 2007

2007-03-13 15:56:19 · 2 answers · asked by Joshua I 1

2007-03-13 15:50:57 · 13 answers · asked by kdsmm 4

2007-03-13 15:48:57 · 3 answers · asked by cyclops 1

A heat engine using 140 of helium as the working substance follows the cycle shown in the figure.

Figure has a "triangle" with coordinates: 1=(1000, 1), 2=(1000, 5), 3=(Vmax, 1)
The cycle starts with 1 and ends at 3. Segment 2-3 is an isotherm and has a curve like half an upward-facing parabola.

What is the temp of the gas at point 1? point 2? point 3?
What is the thermal efficiency?
What is the maximum possible efficiency of a heat engine that operates between and Tmax and Tmin?

2007-03-13 15:46:43 · 1 answers · asked by Anonymous

You are trying to photograph a bird sitting on a tree branch, but a tall hedge is blocking your view. However, as the drawing shows, a plane mirror reflects light from the bird into your camera. The bird is 2.1 m from the mirror. From the camera, the mirror is x=4.5 m and the bird is y=4.6 m from x but 2.4 from y. For what distance must you set the focus of the camera lens in order to snap a sharp picture of the bird's image?

2007-03-13 15:44:09 · 4 answers · asked by layc_510 2

A heat engine using a diatomic gas follows the cycle shown in the figure. Its temperature at point 1 is 20.0 C.

Figure has a triangle with coordinates: 1=(10, 0.5), 2=(40, 1.5), 3=(40, 0.5)
The cycle starts with 1 and ends at 3.

What is the power output of the engine if it runs 100 rpm?

What is the thermal efficiency of this heat engine?

2007-03-13 15:38:35 · 1 answers · asked by Anonymous

2007-03-13 15:17:53 · 4 answers · asked by Taichi 2

2007-03-13 15:12:34 · 5 answers · asked by babykrisbach1 2

2007-03-13 15:04:35 · 4 answers · asked by Jacqueline L 1

Based on their relative speeds, what might you say about elasticity and dencity of silver and glass?

2007-03-13 15:03:13 · 1 answers · asked by Augustblue 1

2007-03-13 14:55:28 · 2 answers · asked by Anonymous

2007-03-13 14:52:33 · 4 answers · asked by Anonymous

A student's car stalls right in front of a speed bump while she is on her way to physics class. To pull it over the bump, she ties a cable to her bumper and to a nearby tree, and pulls with a force, F, of 84.0 lbs (374 N) at the midpoint in a perpendicular direction.
If θ is 10.5°, what is the size of the force pulling the car in lbs?

2007-03-13 14:46:51 · 2 answers · asked by saxeyamber009 1

The ideal gas in a Carnot engine extracts 1000 J of heat energy during the isothermal expansion at 300C.
How much heat energy is exhausted during the isothermal compression at 50C?

2007-03-13 14:45:36 · 1 answers · asked by Anonymous

this light? what color would you observe?

2007-03-13 14:26:06 · 1 answers · asked by pjrlollis 1

energy of a photon of this light?

2007-03-13 14:23:26 · 1 answers · asked by pjrlollis 1

several minutes of contact

2007-03-13 14:12:34 · 5 answers · asked by Anonymous

In a convertor or a transformer, output Power = input Power OR (I out) (V out) = (I in) (V in)

But there are converters with the 120V and 15amps input which only produce 5amps and 12V output. How they work? I mean, Why this converters produce a power much less than the input power?

Actually, if the output voltage is 12V, the output current should be 150amps, but how they produce only 5 amps or even less?

2007-03-13 14:08:46 · 4 answers · asked by ___ 4

The exact questions is: At the moment that two carts collide, they both experience an instantaneous stop. Is momentum conserved during the stop? Give reasons for your answer.

2007-03-13 14:05:41 · 6 answers · asked by Foxybaby1976 3

A 15g marble is dropped from rest onto the floor 1.44m below. (a) If the marble bounces straight upward to a height of 0.640m what is the magnitude and direction of the impluse delivered to the marble by the floor? (b) If the marble had bounced to a greater height, would the impluse delivered to it have been greater or less than the impluse found in part (a)? Explain.

2007-03-13 13:55:02 · 1 answers · asked by christy r 1

A thin rectangular plate of uniform areal density σ = 2.73 kg/m2 has length of 37.0 cm and width of 24.0 cm. The lower left hand corner is located at the origin, (x,y)= (0,0) and the length is along the x-axis.

1) There is a circular hole of radius 7.00 cm with center at (x,y) = (12.50,10.00) cm in the plate. Calculate the mass of plate.

If I find the volume of the plate, I can find the mass, but how do I find the volume if no other dimensions are provided?

2)Calculate the x-coordinate of the center of mass of the plate.

Would an equation like this work?
X = (Xd*Vd - Xh*Vh) / (Vd-Vh)

where Xd = center of mass of the whole object (including
the cut circle)
Vd = surface area of the whole plate
Xh = center of mass of the cut circle ONLY
Vh = surface area of the cut circle ONLY

Thanks in advance for your help.

2007-03-13 13:47:07 · 4 answers · asked by Defcon6 2

A pair of narrow, parallel slits seperated by 0.25 nm are illuminated by the green component from a mercury vapor lamp( lambda= 546.1 nm). The interference pattern is observed on a screen 1.20 m from the plane of the parallel slits. Calculate the distsance from the central maximum to the first bright region on either side of the central maximum and between the first and second dark bands in the interference pattern.

2007-03-13 13:38:31 · 2 answers · asked by Kitana 2

Light of wavelenght 575 nm falls on a double slit, and the first bright slit is seen at an angle of 16.5. Find the distance between the two slits.

2007-03-13 13:32:15 · 1 answers · asked by Kitana 2

i really need help cause we don't have a book for science, and we are supposed to do a crossword puzzle and i need help.

1.__________ discovered that the buoyant force depends on the weight of the displace fluid.
2._______ describes the connection between fluid speed and pressure.
3. a swim ______ controls a fish's overall density.
4._______ force is the upward forces exerted on any object in a fluid.
5.A _____ is something that flows.
6._____ is the upward force due to fluid flow around an airplane wing.
7.The amount of matter in a certain volume divided by the volume is _____.
8.A fluid force that opposes motion is called _______.
9.One Newton per squar meter is a _______.
10.A ______ device uses a liquid to transmit pressure from one point to another.
11.An irregular fluid flow is ________.
12.To __________ is to move into something else's location by pushing it aside.
13._______ is the amount of force exerted on a given area divided by the area.
14.The forward force

2007-03-13 13:29:24 · 4 answers · asked by ☆★♪♫Caitlin♫♪★☆ 2

By the way, use 58 as the molar mass of salt. Oh, and the Kf of water is 1.86ºC/m.

2007-03-13 13:27:37 · 2 answers · asked by Random G 3

from passing through the containment field

2007-03-13 13:25:22 · 2 answers · asked by chingow 2

Sorry, another question for my report
I would find it very helpful if you can help me!

2007-03-13 13:17:14 · 3 answers · asked by ? 3

Ball A (1.0kg) has an initial velocity of 1.8 m/s @ 0 (degrees). Ball A collides with Ball B (2.5kg). Ball B is initially at rest. At impact Ball A keeps going on with a velocity southeast @ 310 (degrees) and Ball B starts moving northeast @ 28 (degrees).

What is the final velocity of both balls?

2007-03-13 13:02:45 · 2 answers · asked by oscarjr1990 2

what is the method of operation for solving all physics problems?? only answer if you know it

2007-03-13 12:44:42 · 3 answers · asked by szewing 2

would it land on someones head? desintagreat on the way down? how high would it go?

2007-03-13 12:42:32 · 8 answers · asked by Anonymous