Physics - October 2007

You are given a vector in the xy plane that has a magnitude of 80.0 units and a y component of -45.0 units.
(a) What are the two possibilities for its x component?
(b) Assuming the x component is known to be positive, specify the vector which, if you add it to the original one would give a resultant vector that is 80.0 units long and points entirely in the -x direction. What is magnitude and what is direction?

2007-10-19 09:38:15 · 1 answers · asked by hahahahahaha 1

in a well defined beam? What kind will spread evenly throughout the room? Roughly what frequency marks the boundary between the two cases?

2007-10-19 09:35:17 · 1 answers · asked by kntagler 1

well i narrowed it down to these to options

a change
or
nuclear fusion

2007-10-19 08:46:34 · 14 answers · asked by Anonymous

okay. i need to kno basicly everything.
in general. i need to know about quarks~~~who discovered them? when? what are they? how do they relate to an atom?....also i need to know about Murray Gell-Mann~who he is. and what he did and why he did it?.
and i need this in a basic view. nothing high tech. i have to teach it to my classmates. uh? also. any ideas on how to make a model of quantum mechanical?. thats a real stumper there!! thank you!

2007-10-19 08:38:02 · 4 answers · asked by Kake 2

the same answer explains also the breaking of a glass cup when something very hot put in it

2007-10-19 08:35:39 · 3 answers · asked by manoura 1

Aluminum rivets used in airplane construction are made slightly too large for the rivet holes to be sure of a tight fit. The rivets are cooled with dry ice (-78.5°C) before they are driven into the holes. If the holes have a diameter of 0.6350 cm at 21.4°C, what should be the diameter of the rivets at 20.5°C if they are to just fit when cooled to the temperature of dry ice?

Ive been trying to figure this one out, if any physics guys know what is going on it would be greatly appreciated. Thanks.

2007-10-19 08:02:56 · 1 answers · asked by Anonymous

An airplane with a speed of 97.5 m/s is climbing upward at an angle of 50 degrees to the horizontal. When the plane's altitudeis 732 m, the pilot releases a package. Relative to the ground, determine the angle of the velocity vector of the package just before impact.

2007-10-19 07:49:26 · 1 answers · asked by Anonymous

Two stones are thrown simultaneously, one straight upward from the base of a cliff and one straight downward from the top of a cliff. The height of the cliff is 6 m, and the stones are both thrown at a speed of 9 m/s. The height above the ground at which they cross is...

2007-10-19 07:16:26 · 1 answers · asked by Anonymous

This has to do with Newtons Law. Thanks a lot guys.

Question: Two buckets of sand hang from opposite ends of a rope that passes over an ideal pulley. One bucket weighs 105 N; the other bucket weighs 48 N. (Assume no friction)

a.) Initially, you hold onto the lighter bucket to keep it from moving. What is the tension in the rope?

_______ N

b.) You release the lighter bucket and the heavier one descends. What is the tension in the rope now?

_______ N


c.) Eventually the heavier bucket lands and the two buckets come to rest. What is the tension in the rope now?

_______ N


Again thanks a lot!!!

2007-10-19 07:03:14 · 5 answers · asked by acousticplaya90 1

a box is given a push so that it slides across the floor. How far will it go, given that the coeffficient of kinetic friction is 0.19 and the push imparts an initial speed of 4.1 m/s?

2007-10-19 06:52:41 · 3 answers · asked by matt c 1

Is carbon dioxide heavier than oxygen?

2007-10-19 06:47:08 · 0 answers · asked by Andy H 1

A baseball player slides into third base with an initial speed of 4 m/s. if the coefficient of kinetic friction between the player and the ground is .46, how far does the player slide before coming to rest?

2007-10-19 06:13:49 · 1 answers · asked by mmeee 1

A uniform disk with a mass of 35.5 kg and a radius of 0.424 m is free to rotate about a frictionless axle. Forces of 90.0 N and 125 N are applied to the disk, as the drawing indicates.

(a) What is the net torque produced by the two forces?
(b) What is the angular acceleration of the disk?

2007-10-19 06:11:47 · 2 answers · asked by Jerry M 1

A 125-g mass is placed on one pan of a balance, at a point 24 cm from the support of the balance. What is the magnitude of the torque about the support exerted by the mass?

2007-10-19 06:05:33 · 1 answers · asked by Anonymous

A centrifuge has a rotational inertia of 7.24 10-3 kg ·m2. How much energy must be supplied to bring it from rest to 419 rad/s?

2007-10-19 06:02:27 · 2 answers · asked by Anonymous

A velodrome is built for use in the Olympics (the figure below). The radius of curvature of the surface is 15.7 m. At what angle should the surface be banked for cyclists moving at 15 m/s? (Choose an angle so that no frictional force is needed to keep the cyclists in their circular path. Large banking angles are indeed used in velodromes

the angle answers should be in degrees, please besides answering it, explain the problem to me, I dont know where to start or anything, thank you!

2007-10-19 05:03:04 · 3 answers · asked by ? 2

does it continuously travel in the space?

i am really interested in finding out the answers.

2007-10-19 04:49:28 · 7 answers · asked by Buknoy 1

1) A car moves with uniform velocity, v1, for one-third of its journey. The car then moves with velocity v2=20 km/h to complete the journey. If the average velocity of the car is 27 km/h for the whole journey, find v1.

Can you pls show the formula and workings to complete this question? thank you!

2) A pupil runs round a circular field of radius 70 km. If he uses 40 minutes to complete one round, what is his velocity?
Is the answer 0km/min or 11km/min? Since velocity is related to displacement and the pupil's displacement remains 0.

Thank you for taking this time to answer my questions... =)

2007-10-19 04:35:52 · 3 answers · asked by anonymoustjl 2

gravity be used to transport information from point a to point b without time being a factor?

http://www.metaresearch.org/cosmology/speed_of_gravity.asp

2007-10-19 04:29:48 · 11 answers · asked by impstout2 4

what is the derivation of

a = g times m over m plus M

a= acceleration
g= gravity
m= mass
M = mass of the glider

explanation please thank you

2007-10-19 04:20:21 · 2 answers · asked by azra k 1

2007-10-19 04:09:25 · 1 answers · asked by CST 1

2007-10-19 04:05:21 · 3 answers · asked by CST 1

whom says he can prove God exists?

2007-10-19 04:01:35 · 4 answers · asked by Life goes on... 6

2007-10-19 03:55:18 · 2 answers · asked by edd 1

A crate is given an initial speed if 3.0m/s up a 25 degrees plane. How far up the plane will it go? How much time elapses before it returns to its starting point? assume mu=0.17.

2007-10-19 02:46:16 · 2 answers · asked by Anonymous

I take cold water in my tea to cool it down a bit - because I don't drink milk. I've noticed that every time I add the water it splashes very high. But the second time I add the water from exactly the same height, it doesn't splash to anywhere near as high. This always strikes me as a bit strange... Is there some stored energy which exists in undisturbed water and its surface tension, and is released upon the first adding of water, but not the second? Perhaps such an effect could be used to harvest extra energy from free standing water, maybe to build a perpetual motion machine extracting energy from the oceans? Or perhaps the water surface has an intricate fractal energy field, and is an example of a fifth force of nature? There's definitely new physics here.

2007-10-19 02:26:24 · 2 answers · asked by David R 1

I have searched and can't find the answer. I can get extra credit for this and time is running out!

2007-10-19 02:25:46 · 3 answers · asked by yenolat 1

2007-10-18 23:46:26 · 6 answers · asked by Ruby Tuesday 2

2007-10-18 21:10:52 · 3 answers · asked by deeloc 3

for example: if im going almost at the speed of light in my car, does my weight change? do i lose weight? gain weight?

2007-10-18 20:55:55 · 17 answers · asked by Anonymous