Physics - December 2007

1. What is its volume?
Express your answer using two significant figures.

2. The ingot is suspended from a rope and totally immersed in water. What is the tension in the rope (the apparent weight of the ingot in water)?
Express your answer using two significant figures.

2007-12-06 04:11:58 · 3 answers · asked by Bugz 3

convert 110km/hr to m/s

2007-12-06 03:38:44 · 2 answers · asked by allee010 1

pls give scientific answers

2007-12-06 03:22:58 · 5 answers · asked by abhay o 1

when we see in mirror why we see our left and right hand opposite to that it is,why we not see our vertical inversion,as head down and legs up???

2007-12-06 01:31:02 · 3 answers · asked by bittu m 1

Lead pellets, each of mass 2.00 g, are heated to 200°C. How many pellets must be added to 450 g of water that is initially at 20.0°C to make the equilibrium temperature 25.0°C? Neglect any energy transfer to or from the container.

2007-12-06 01:01:05 · 4 answers · asked by swimchic632 2

2007-12-06 00:47:12 · 1 answers · asked by renedelgado39 1

I've been trying this all night. Can someone please help?
Two particles of masses M1=63000kg and M2=7200kg are initially at rest an infinite distance apart. As a result of the gravitational force the two masses move towards each other. Calculate the speed of M1 when their separation distance is 41.3km.

I've tried using conservation of potential energy, but I get stuck. Can anyone please help?

2007-12-06 00:02:22 · 4 answers · asked by stud muffin 2

A programme on Sky News recently claimed computers are now producing as much CO2 as aircraft; I am at a loss as to the mechanism by which this happens.

2007-12-05 23:15:22 · 7 answers · asked by Bigosi 2

2007-12-05 23:11:19 · 15 answers · asked by Anonymous

2007-12-05 19:56:25 · 5 answers · asked by this is my avatar 4

then can they be changed so that they dont repel directly upwards but to a spesific direction....so if a ball was aplied to this "super" surface, it would spin in a clock wise direction, therfore spinning an axle...........

i know it sounds crazy.....but hey haha

2007-12-05 19:45:54 · 4 answers · asked by Anonymous

i have searched and searched yet i can not find it.....

maybe you can help


(yes ......YOU!!!!)

2007-12-05 19:24:52 · 6 answers · asked by Anonymous

The threshold of hearing is defined as the minimum discernible intensity of the sound. It is approximately 10^-12 W/m^2 . Find the distance from the car at which the sound from the stereo can still be discerned. Assume that the windows are rolled down and that each speaker actually produces 0.06 W of sound, as suggested in the last follow-up comment.

2007-12-05 19:17:58 · 1 answers · asked by Anonymous

i need despirate help with my assesment plz

some one

2007-12-05 18:58:15 · 4 answers · asked by Anonymous

If the the space-time 'curvature' proposed by Relativity is real, wouldn't the curvature have to be through a higher dimension, since we can't see it? Think of the 2-dimensional grid diagram they use to illustrate gravity sometimes. Now extend that grid into 3 dimensions, creating a lattice. Now place a mass at the center of one of the cubes in that grid. What happens? The cube 'shrinks' a little, dragging the lines to the other cubes (spacetime) with it. That's the spacetime distorion (curvature) caused by gravity. If you think about that models of a tesseract you've seen, one cube inside the other, you see that gravity must be a 4th dimensional vector. It's relatively (!) easy to visualize if you think about it that way.

2007-12-05 18:12:36 · 4 answers · asked by AmigaJoe 3

a model airplane has a mass of .9 kg and moves at a constant speed in a circle that is parallel to the ground. Find the tension T in the guideline (length = 17 m) for speeds of 19 m/s and 38 m/s.

b) if the model airplane has a speed of 28m/s and a mass of .9 kg. The plane flies ona circle that is parallel to the ground. Find the Tension T in the guidelines whose lengths are 11 m and 22m

2007-12-05 16:59:43 · 2 answers · asked by Anonymous

The reason I ask is because everyone says that nothing can travel faster but I always thought maybe we wouldn't know if something did because it would be beyond our visual abilities. Thanks

2007-12-05 16:44:00 · 6 answers · asked by Anonymous

An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle is 446 Hz when the train is approaching him and 442 Hz when the train is receding from him. From this he can find the speed of the train. What value does he find?
_______m/s (Assume the speed of sound is 345 m/s.)

2007-12-05 16:43:04 · 5 answers · asked by Anonymous

Please show all formulas and steps.

A cylindrical diving bell 3.0 m in diameter and 4.1 m tall with an open bottom is submerged to a depth of 225 m in the ocean. The surface temperature of the water is 25°C, and the temperature 225 m down is 5.0°C. The density of sea water is 1025 kg/m3. How high does the sea water rise in the bell when the bell is submerged?


First to have correct answers receives ten points.

Thank you very much.

2007-12-05 16:37:12 · 1 answers · asked by none 2

An inventor proposes to make a pendulum clock using a pendulum bob with mass m at the end of a thin wire of length L. Instead of swinging back and forth, the bob moves in a horizontal circle with constant speed v, with the wire making a constant angle beta with the vertical. Assuming that the time T for one revolution is known, find thetension F in the wire and angle beta. (derive the equation)

i honestly do not understand what this is asking me to do. And i do not understand how to solve without being given any values, any help is much appreciated.

2007-12-05 16:30:31 · 3 answers · asked by Anonymous

I cannot seem to get a straight answer on this... My initial assumption is no, but that is based on the assumption that the speed of sound is constant, and only changing the medium's density or temperature could change it.

2007-12-05 16:17:31 · 4 answers · asked by kbomb2121 2

2007-12-05 16:10:46 · 2 answers · asked by Anonymous

A tennis ball, starting from rest, rolls down the hill in the drawing. At the end of the hill the ball becomes airborne, leaving at an angle of 35° with respect to the ground. Treat the ball as a thin-walled spherical shell, and determine the range x.

I dont have a picture of the drawing but the ball rolls down a hill, goes back up slightly then launches at a angle of 35 degrees. the point at which the ball is launches is at the same height as where the ball lands. Also the vertical height from where the ball starts rolling down the hill to the height it is launched from is 1.8m.
I know the Inertia of a hollow shell sphere is I=(2/3)mr^2

2007-12-05 15:58:58 · 2 answers · asked by Anonymous

An ambulance with a siren emitting a whine at 1,600 Hz overtakes and passes a cyclist pedaling a bike at 2.44 m/s. After being passed, the cyclist hears a frequency of 1,590 Hz. How fast is the ambulance moving?

Explain your work. Thanks! :)

2007-12-05 15:33:41 · 1 answers · asked by Anonymous

I heard somewhere that useful energy might someday be harvested from this effect. So what is it called?

2007-12-05 15:28:37 · 3 answers · asked by Yaakov 6

please explain what part(s) of its path does a projectile have minimum speed?

i really dont understand this, please explain using easily understandable words THANKS!

2007-12-05 15:27:17 · 2 answers · asked by Anonymous

1) In which of the following cases will the images have similar properties: concave mirror, convex mirror, concave lens, convex lens?

2) Can you get an image on the screen when the distance between the object and the mirror or lens is less than the focal length? explain.

Thanks!

2007-12-05 15:04:30 · 1 answers · asked by La_rr 1

i have to write a report on ionized lifters, and i was wondering how do they work. what is the physics behind them? please be as detailed as possible, or point me to the right direction to find information about them.

2007-12-05 14:57:07 · 2 answers · asked by Anonymous

a stationary motion detector sends sound waves of frequenct 0.150 MHz toward a truck approaching at a speed of 45.0 m/s. What is the frequency of the waves reflected back to the detector?

Explain your work. Thanks! :)

2007-12-05 14:24:16 · 1 answers · asked by Anonymous

If
Pi1: 3x-2y+z-5=0
Pi2: x+y - 2z +3=0

If the two planes are not parallel, what is the equation of the intersection line?

2007-12-05 14:20:26 · 3 answers · asked by Mayx 3