Physics - February 2007

A rectangular loop of wire is moving toward the bottom of the page with a speed of 0.025 m/s (see the drawing). The loop is leaving a region in which a 2.2 T magnetic field exists; the magnetic field outside this region is zero. During a time of 2.0 s, what is the magnitude of the change in the magnetic flux?


This is the drawing
http://www.webassign.net/CJ/22_16.gif

2007-02-18 06:48:46 · 1 answers · asked by Hey Carl 1

2007-02-18 05:41:19 · 7 answers · asked by Carol E 1

2007-02-18 05:37:17 · 8 answers · asked by Anonymous

Why would a pumped up football bounce more if you dropped it from a metre than, say, a half flat ball? What is it about having more pressure in the ball that makes it bounce higher when it is rising?

2007-02-18 05:31:14 · 6 answers · asked by alex_isaacs 1

2007-02-18 05:27:09 · 3 answers · asked by Melissa 2

Please explain

2007-02-18 05:25:35 · 1 answers · asked by Melissa 2

2007-02-18 05:24:18 · 11 answers · asked by Melissa 2

A 71.4 kg man steps off a platform 3.49 m above the ground. He keeps his legs straight as he falls, but at the moment his feet touch the ground his knees begin to bend, and, treated as a particle, he moves an additional 0.59 m before coming to rest. Treating our rigid legged friend as a particle, what is the average force his feet exert on the ground while he slows down?

Assume the acceleration while he is slowing down is constant.

Answer= 4839 N. How do you do this?

2007-02-18 05:08:36 · 2 answers · asked by soulen3 2

2007-02-18 04:54:27 · 4 answers · asked by alone 2

I'm having trouble with these two problems on my physics homework. Any help would be appreciated.

1. Two charged spheres each containing a quantity of excess electrons equal in number to Avogadro's number are separated by 1000 km in vacuum. Compute to two significant figures the electrical interaction between the spheres.

2. Two protons are fired directly at each other in a vacuum chamber. What is the force each experiences at the instant they are 1.1 10-14 m apart? [Hint: The particles are identically charged and will experience a Coulomb repulsion.]

2007-02-18 04:36:48 · 1 answers · asked by oriolesfan2323 4

2007-02-18 04:34:39 · 2 answers · asked by Ricardo W 1

A mass of 0.380 kg hangs from a string wound round the cylinder.
(a) when the system is released from rest, the mass takes 2.0 s to fall through a height of 5 m. What is the moment of inertia of the cylinder?
(b) The cylinder is then replaced by a hollow cylinder of the same mass and dimensions. Discuss qualititively the effect on (i) the speed of the mass (ii) the rotational kinetic energy of the cylinder, when the mass falls through a height of 5 m

2007-02-18 04:25:28 · 2 answers · asked by HeiglLee 2

Is it possible that in alternate/paralell universes, different law of physics apply in such a way that math is even different.

For example, kicking a football in this universe propells it forward.
In the other universe, it turns inside-out.

In this universe 1+1=2
In the other universe 1+1=3

But if 1+1=3, then if it is logical to get from this universe to the other by going direction A, going the reverse direction afterwould would not get us back to this universe.

Indeed logic may be such that the concept its self of being able to do so may be redundent.
Indeed logic it's self may be redundent.
If so, what would replace it, or would it matter if there is no logic to make it matter?

If it doesn't, they how do we know existance it's self is even relavent. It may be something else altogether.

Is this how confusing alternate realities could be?

2007-02-18 04:05:30 · 3 answers · asked by Anonymous

a) Of the astrophysical ones, of the nuclear astronomers, and the physicists: Light, atomic waves of the average length caused by the jumps of electrons inside of the atom. (Only Recognizing the nucleus “sun”)
b) of the great atom (universe): That it is divided in three energies: Prótons, Elétrons and Nêutrons. In the sun, it was the positive power (Prótons), but with the negative return (electrons). In the Interstellar system, it was the negative power (electrons), but with the positive return (Prótons). In what it says respect to the land, was with the responsibility of the Nêutrons, acting the end to unbalance the positive and negative forces in its related limits. Thus, it neutralizes the start and the extremity. The energies that come of the place for where to go, and go for the place of where they come. As the diagram of Tarcísio Brito (...).

2007-02-18 02:37:52 · 2 answers · asked by britotarcisio 6

A. only momentum is conserved
B. only energy is conserved
C. both energy and momentum are conserved

2007-02-18 02:24:31 · 6 answers · asked by Anonymous

A. a non-zero Kinetic energy
B. a non-zero Gravitional Potential Energy
C. a non-zero Momentum
D. a non-zero Mass
E. a non-zero Velocity

2007-02-18 02:21:09 · 6 answers · asked by Anonymous

Which object has a higher temperature?

A. Metal Leg
B. Desktop
C. They are they same
D. Not enough information to tell

2007-02-18 02:10:45 · 2 answers · asked by Anonymous

2007-02-18 02:00:13 · 2 answers · asked by Vinny D 1

I'm a bit confused about the difference in calculating work done in vertical and horizontal directions.

WorkDone = Force x DistanceMoved. For forces in a vertical direction the WorkDone is equal to the gravitational potential energy gained. So, the work done lifting a 2kg book through 1.5m is (about) 30 J.

Some books will ask questions of the form: how much work is required to move a 2kg across a 1.5m table? If the book has a weight of (about) 20 N then the answer we arrive at is 30 J.

But intuitively, it is (normally) easier to move things across than it is up - the answers shouldn't be equal.

So am I right in saying that the weight of the book isn't, on its own, important for calculating work done moving the book across the table? And that, in addition, for example, we would need things like surface area, friction per unit of surface area? In other words, it is the force required to move the book rather than weight of the book that is important?

2007-02-18 01:55:09 · 4 answers · asked by Grant V 1

2007-02-18 01:36:13 · 2 answers · asked by Anonymous

How much pressure is there at the bottom of 220 m of water, not counting atmospheric pressure? I know that it's density x acceleration x height, so is the answer 2156000 pascals? Is the unit correct?

2007-02-18 01:25:42 · 4 answers · asked by Anonymous

2007-02-18 01:21:19 · 3 answers · asked by Anonymous

52 kg box pushed 7 m acoss floor by force p whos magnitude is 163N... the force is parallel to the displacement of the box. the coefficient of kinetic friction is .25. determine the work done on box by each of 4 forces that act on box. Include proper plus or minus sign.


a/. applied force.
b. frictional force.
c. Normal force
d. gravity

I got all right except for frictional force how do you find this? why is it not juts the negative of applied force? thank you

2007-02-18 00:33:17 · 4 answers · asked by Anonymous

ok... an 80 kg skier rides a 2700 m long lift to the top of a mountain. the lift makes 14.9 degree angle w/ horizontal what cvhange in skiers gravitational potential enery......

i tried to use w=mg(cos theta) (h0-hf) but i got wrong answer is this the wrong formula... maybe i am pluggin this in all wrong? please explain

2007-02-18 00:28:46 · 3 answers · asked by Anonymous

I have a physics question...Please if you understand explain this to me....I do not want anyone to do this for me I need explanation....b/c I wil need to understand this stuff when i take teh test so please explain adn talk me through this problem....

A skier, starting from rest, coasts down a mountain that makes an angle 25 degrees with the horizontal. The coefficient of kinetic friction between the snow and skis is .200. she coasts for 8.4 m before coming to the edge of a cliff.. Without slowing down, she skis off the cliff and lands downhill at a point whose vertical distance is 3.80 m below the edge. How fast is she going just before she lands?

It says that this correlates the the work energy theorem and kinetic energy ... i read the sections and example problems and still have no idea where to even begin. Please help....thank you

2007-02-18 00:17:37 · 3 answers · asked by imjustmewhatelseshouldibe 1

2007-02-18 00:04:33 · 1 answers · asked by nad 1

2007-02-17 23:47:45 · 6 answers · asked by angel 1

Two particles, of masses x kg and 0.1kg, are moving towards each other in the same straight line collide directly. immediately before the impact, the speeds of the particles are 2ms-1 and 3ms-1 respectively.

a) Given that both particles are brought to rest by the impact, find x?

b) Given instead that the particles move with equal speeds of 1ms-1 after the impact, find the three possible values of x?

2007-02-17 23:38:55 · 2 answers · asked by Leonidus 2

2007-02-17 23:33:21 · 8 answers · asked by shaunak d 1

2007-02-17 23:23:20 · 13 answers · asked by Anonymous