Physics - December 2006

I pretty much understand it but i was just wondering if there was anything i missed. Just tell me everything u know on it. Im just interested

2006-12-18 14:38:56 · 3 answers · asked by gtarplyr98 1

A disk of negligible mass and radius 22 cm is constrained to rotate on a frictionless axis about its center. On the disk are mounted masses of 25 grams at a distance of 16.06 cm from the center, 6 grams data distance of 9.02 cm from the center and 31 grams at a distance of 4.4 cm from the center. A uniform force of .06983 Newtons is applied at the rim of the disk in a direction tangent to the disk.
•What torque is applied to the disk?
•What will be the resulting change in the angular momentum of the disk if the torque is applied for `dt = 4 seconds?
•What is the resulting change in the velocity of the disk?
•If the disk starts from rest, through what angular displacement will it rotate during the `dt seconds?
•Through what distance will the rim move during this time, and how much work is therefore done by the applied force in this time?
•What is the kinetic energy of the disk, as calculated using its initial and final angular velocities and moment of inertia?

2006-12-18 14:35:08 · 1 answers · asked by tanie 1

1. What is the horizontal force necessary to drag a brick that weighs 60 N on a wooden table (µk= 0.7) at constant velocity?
1.1 if you pull on the brick horizontally with a force of 80 N, what is its acceleration?

2006-12-18 14:23:04 · 3 answers · asked by vintagex50s 2

1. The Druids who built stonehenge had to contend with lots o' friction. If the coefficient of friction between stone and dirt is µk=0.6, a) what would be the force necessary to drag a 1300 kg rock at constant velocity? (You must find the weight of the rock first!!)
1.2 if the rock was dragged by a rope horizontally with a force of 19000 N, what is its acceleration?
2. What is the acceleration of a 19 kg sled with plastic runners on dry snow (µk=0.3) if a horizontal pulling force of 100 N is applied to it?
2.2 how much force must it be pulled with so it goes at a constant velocity?
3. What is the acceleration of a 4 kg crate, if you push it with a force of 110 N, and the coefficient of kinetic friction between the crate and the floor is µk=0.3?
3.1 how much force must it be pushed with so it goes at a constant velocity?

2006-12-18 14:21:01 · 3 answers · asked by vintagex50s 2

2006-12-18 14:15:33 · 1 answers · asked by nobody 1

before that, i need someone to explain how newton's third law can be applied to lift, since Bernoulli effect has a smaller influence. Since the aerofoil pushes against the air, so what? Wouldnt there simply be a drag force? Where does the lift come from?
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Ok, here's the question i need help with.
1. Why Frisbees fly (i guess i can do it nicely in terms of Bernoulli principle, but i want to know the Newton's way.)
2. Why do Frisbees fly in a more controlled manner when they are spinning.
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Here's a guess for 2. I read beforehand that if u hold the centre of a wheel of a bike and asked someone else to spin it, u will feel a mysterious force if u try to tilt it to anyway. I cant visualize it, but i can understand what they mean by tilting it is changing its direction and so the angular velocity changes, which constitutes a force. Hope there is some way u can help me in my understanding..=)
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(i know its a lot to deal with here, sorry...a good answer gets my ten points)

2006-12-18 13:24:04 · 7 answers · asked by luv_phy 3

2006-12-18 12:55:41 · 3 answers · asked by Jose C 1

2006-12-18 12:34:32 · 4 answers · asked by Jose C 1

2006-12-18 12:32:11 · 5 answers · asked by wathupdawg 1

2006-12-18 12:31:43 · 5 answers · asked by Jose C 1

how does flying defy the laws of physics?
i know it seems really random and easy but i really need some help

2006-12-18 12:30:42 · 7 answers · asked by Valerie 3

Please explain the equation

2006-12-18 12:13:09 · 2 answers · asked by supercalofragilistic 3

http://img186.imageshack.us/img186/2781/symhu0.jpg

I forgot... is it directly related to?

2006-12-18 12:01:11 · 12 answers · asked by Anonymous

2006-12-18 11:37:04 · 4 answers · asked by Anonymous

The railroad car has a mass of 13,500 kg. It travels alone on a level frictionless track with a constant speed of 17.0 m/s. A 5,500 kg additional load is dropped onto the car. What is the car's new speed???

Can't get the answer... please help ASAP. Thanks!!!

2006-12-18 11:36:30 · 2 answers · asked by abc123 1

is [cold=sin(o)] the imaginary form of real [heat=cos(o)]? and is this cold the essence of the vacuum of space? if so, it seems that the "big bang" theory began not with a singularity expanding yet with an infinite "cold disintegration" ever inward ... subjectively, that the background radiation is a doppler red shift leaving this universe for a point singularity that is the anti-matter infinity? has this been theorized much less proven or disproven? would then creation be self-activating...being the presence of the infinite vacuum of imaginary cold space a single object with no real reference disintegrating ever inward creating thermodynamic differences?

2006-12-18 11:35:24 · 2 answers · asked by stevenos_2005 2

if no friction is involved, mechanical energy is never created or destroyed, just transformed from one form to another. with this priniciple in mind, answer the following question: a ball with a mass of 0.15 kilograms is thrown to a height of 3.0 meters. how far is it traveling as it leaves the throwers hand?(assume there is no friction)

2006-12-18 10:59:59 · 5 answers · asked by Purple C 1

The Sojourner rover vehicle was used to explore the surface of Mars as part of the pathfinder mission in 1997. Use the data below to answer the question that follow.

Mars Data:
Radius = 0.53 x Earth's radius
Mass = 0.11 x Earth's mass

Soujourner Data:
Mass of Sojourner vehicle = 11.5kg
Wheel diameter = 0.13 m
Stored energy available = 5.4 x 10^5 J
Power required for driving under average conditions = 10W
Land Speed = 6.7 x 10^-3 m/s

a) Determine the acceleration due to gravity at the surface of Mars in terms of g, the acceleration due to gravity at the surface of Earth.

b) Calculate the Sojourner's weight on the surface of Mars.

c) Assume that when leaving the pathfinder spacecraft, Sojourner rolls down a ramp inclined at 20r (? I don't know this symbol, it looks like a big r that also looks like v) the horizontal. The ramp must be lightweight but strong enough to support Sojourner. Calculate the minimum normal force that must be supplied by the ramp.

2006-12-18 10:59:55 · 3 answers · asked by Robert G 1

Einstein stated in his theory of relativity that if a person could travel at least 80 percent near the speed of light, that time for that person will pass more slowly relative to time for an earthbound person. So logically, anytime I am in my car moving, time is moving slowly compare to my housebound girlfriend? So in essence will you say I am younger in terms of age relative to my girl friend's age? Will Einstein clock paradox problem apply even though I am not moving 80 percent near the speed of light. What make the speed of light so special?

2006-12-18 10:44:00 · 4 answers · asked by Anonymous

A 0.70 kg block is hung from and stretches a spring that is attached to the ceiling. A second block is attached to the first one, and the amount that the spring stretches from its unstrained length triples. What is the mass of the second block?

2006-12-18 10:43:28 · 5 answers · asked by candy 3

If the cart starts from rest at 52 meters above ground, what is the speed of the coaster when it gets to 13 meters. (assume that all PE is converted to KE)..... Any ideas on how to do this and show work for it.

2006-12-18 10:31:49 · 5 answers · asked by Anonymous

The rings of a Saturn-like planet are composed of chunks of ice that orbit the planet. The inner radius of the rings is 69,000 km, while the outer radius is 155,000 km.The mass of this planet is 4.25 *10^26 kg.
Find the period of an orbiting chunk of ice at the inner radius

2006-12-18 10:27:51 · 3 answers · asked by tjmierzwa 2

A person can change the volume of his body by taking air into his lungs. The amount of change can be determined by weighing the person underwater. Suppose that underwater a person weights 20.0 N with partially full lungs and 40.0 N with empty lungs. Find the change in body volume.

2006-12-18 10:17:52 · 2 answers · asked by candy 3

what is a double sine wave? as in the sentence " You are engulfed in double sine waves" any one know?

2006-12-18 10:13:03 · 2 answers · asked by ashnicsmi 2

Can a blindfolded person walk in a circle?

2006-12-18 10:03:17 · 7 answers · asked by Alvina L 2

Why is this so? How do this relates to Illusion and Matter? Plus, the meaning this information shines onto our life within this vast universe or mega-multi-verses.

2006-12-18 09:55:47 · 4 answers · asked by Zubli Zainordin 1

Need Help. I get 1.9949 * 10^-8 but it says its wrong. Can someone help me. Four 8.5 kg spheres are located at the corners of a square of side 0.68 m. Calculate the magnitude and direction of the gravitational force on one sphere due to the other three.

2006-12-18 08:59:31 · 5 answers · asked by tjmierzwa 2

2006-12-18 08:58:29 · 9 answers · asked by Dj Smith 1

In theory, I would imagine that with several thousand volts with low amps, one could withstand this much power and not be electrocuted, right. Then how many volts and amps does the electric chair use and what is the minimum power requirement that would fry the prisoner. The electric chair is hardly used anymore, in favor of lethal injection and to me, the chair would be cruel and punishment overkill. Just curious on the power issue.

The movie, The Green Mile, had a very disturbing electric chair scene which really seemed real. When they fired up the chair, the whole prison's lighting system started flickering and dimmed out

2006-12-18 08:51:09 · 4 answers · asked by mrfrudd2006 3

2006-12-18 08:37:07 · 4 answers · asked by khaled e 1