Physics - March 2007

options:mesons, photons,leptons,baryons..please explain

2007-03-19 20:28:55 · 1 answers · asked by Anonymous

A roller-coaster car goes around a vertical circular loop-the-loop with a diameter of 50.0 m. Ignoring friction, what is the minimum speed of the car at the top of the loop so that the car stays in contact with the track?

2007-03-19 19:56:34 · 2 answers · asked by Ny 1

or is there in fact a physical reality that exists independently from our perceptions?

2007-03-19 19:43:40 · 5 answers · asked by Anonymous

Is it true that in other parts of the world the vortex goes counter clockwise?

2007-03-19 19:04:55 · 5 answers · asked by wizardofoz 1

A lawn mower has a flat, rod-shaped steel blade that rotates about its center. The mass of the blade is 0.74 kg and its length is 0.56 m.
(a) What is the rotational energy of the blade at its operating angular speed of 3500 rpm? kJ
(b) If all of the rotational kinetic energy of the blade could be converted to gravitational potential energy, to what height would the blade rise? m

2007-03-19 18:39:58 · 1 answers · asked by Anonymous

two parallel wires going in the same direction.
i1 i2
l l
l l
l l
l l

the magnetic field of i1 is circular (think right hand rule pertaining to a straight wire)

using the other right hand rule (not the one with the circular loop, but the one with the force, magnetic field, and current) how can we determine the direction of the force on i2?

I just can't picture it. I've already tried using the right hand rule, but I'm confused. The only direction I get for the force is up, which is totally wrong.

2007-03-19 18:11:23 · 2 answers · asked by EGGO 2

I'm doing a physics homework about magnetism and I need to know how the Internet relates to it, maybe it has to do with electromagnetic waves or something, someone please help

2007-03-19 18:01:11 · 3 answers · asked by needhelpnow! 1

A 3 kg block starts from rest at the top of a 30 degree incline and slides a distance of 2m down the incline in 1.5s. Find a) the acceleration of the block, b) the coefficient of kinetic friction, c) the frictional force acting on the block, and d) the speed of the block after it has slid 2m.


Three blocks are in contact with each other on a frictionless horizontal surface. A horizontal force of 18N is applied to the first block. Find a) the acceleration of the blocks, b) the resultant force on each block, and c) the magnitude of the contact forces between the blocks. (The blocks' masses are, in order, 2kg, 3kg, 4kg)

Oh, and this isn't homework or a quiz or anything, just some concepts I'm struggling with.

2007-03-19 17:58:10 · 2 answers · asked by Hopeless_Romantic 2

Consider three capacitors in parallel, each with a value of 25.0uF. Also consider an Ammeter placed on the first wire coming out of the positive power feed, breaking the circuit there (this then goes back into the circuit, to the positive side of the capacitors). A potential difference of 4200 V is then established through the circuit. How many coulombs pass through the ammeter? Can you explain your answers?

2007-03-19 17:53:32 · 1 answers · asked by Anonymous

2 forces 170lbs and 220lbs act on the same object at angles of 37 and 257 degrees

2007-03-19 17:33:20 · 1 answers · asked by Anonymous

(The answer is not 1 m/s.)

2007-03-19 17:32:50 · 3 answers · asked by mothsandbutterflies 1

a hammock is supported by two hooks at the same level. a man is seated in this hammock. at what angle relative to the horizontal will the tension in each suspending rope ( hence the pull on each hook) be equal to the mans weight?

2007-03-19 17:13:34 · 1 answers · asked by Anonymous

the person outside cannot see the person inside.
Explain this please???

2007-03-19 17:11:42 · 8 answers · asked by mothsandbutterflies 1

heres the list: speed velocity, mass, weight, work, torque and volume which ones are scalar and which ones are vectors

2007-03-19 17:10:24 · 5 answers · asked by Anonymous

I am wonderng, which would have the stronger magnetic field, an uninsulated wire carrying current
an insulated wire carrying the same current.

( Not sure if I can make my electromagnet stronger by removing the insulation).

2007-03-19 16:56:21 · 4 answers · asked by Anonymous

A 17 g rifle bullet traveling 200 m/s buries itself in a 3.5 kg pendulum hanging on a 2.7 m long string, which makes the pendulum swing upward in an arc. Determine the vertical and horizontal components of the pendulum's displacement.

2007-03-19 16:53:59 · 2 answers · asked by Jessie L 2

2007-03-19 16:53:21 · 1 answers · asked by Anonymous

Can't quite figure this one out.

A block of mass m is placed in a smooth-bored spring gun at the bottom of the incline so that it compresses the spring by an amount x_c. The spring has spring constant k. The incline makes an angle theta with the horizontal and the coefficient of kinetic friction between the block and the incline is Mu. The block is released, exits the muzzle of the gun, and slides up an incline a total distance L .

Find , the distance traveled along the incline by the block after it exits the gun. Ignore friction when the block is inside the gun. Also, assume that the uncompressed spring is just at the top of the gun (i.e., the block moves a distance while inside of the gun). Use g for the magnitude of acceleration due to gravity.

Express the distance L in terms of x_c, k, m, g, Mu, and theta .


Approach I took:

K1 + U1 + U_grav = K2 + U2 + U_grav

0 + .5kd^2 + 0 = 0 + 0 + (mu)mgDsin(theta)

D = (kd^2) / 2((Mu)mgsin(theta)

Incorrect, however. It's exactly like another problem we did in class but that one did not have friction as a variable. So I'm sure that's where my mistake lies. Any ideas?

2007-03-19 16:37:20 · 1 answers · asked by Dathan C 2

I own a huge 200lb rubberband ball. I am going to drop it off a bridge thats around 150ft high onto an old road. WILL IT CRACK OR PUT A CRATER IN THE ROAD? Even though the ball is made of rubber it is extremely dense. what do you think?
Thanks

2007-03-19 16:33:53 · 6 answers · asked by Ziema Diema 1

2007-03-19 16:27:45 · 4 answers · asked by Anonymous

2007-03-19 16:23:25 · 5 answers · asked by aunt boo 1

i'm in intro to science, and we started a new unit on waves and vibrations, i'm guessing it has something to do with vibrations...could you help me out plz...thx

2007-03-19 16:21:45 · 3 answers · asked by [milk·bone] 2

2007-03-19 16:16:22 · 1 answers · asked by pinay804 2

2007-03-19 15:41:34 · 2 answers · asked by pinay804 2

My toddler can only sleep with a cd player playing classical music in his room. I am just wondering if the cd player transmits electromagnetic waves, and if so, is it dangerous for my baby's brain development? thanks for your answers.

2007-03-19 15:34:02 · 3 answers · asked by chomar 2

A Boeing 747 jet with a wingspan of 60m is flying horizontaly at a speed of 300m/s over Phoenix, Arizona at a location where the Earth's magnetic field is 50 micro tesla at 58 degrees below the horizontal. What voltage is generated between the wingtips ?

2007-03-19 15:31:36 · 1 answers · asked by Anonymous

Would you be able to see the road with your headlights on?

2007-03-19 15:30:11 · 9 answers · asked by FarOut 4

If you fire a ball through a pile of sand it will slow down and emerge at less than its initial speed. But when light slows down inside a pane of glass it reemerges at the initial air speed. WHY?

2007-03-19 15:19:14 · 2 answers · asked by Bruno S 3

Show working

2007-03-19 15:17:47 · 5 answers · asked by ogunro a 2

Physics

2007-03-19 15:15:20 · 1 answers · asked by Mujahid E 2