Physics - November 2006

filled w/ helium plus air at atmospheric pressure is designed to support a mass of 117 kg (payload + empty balloon). Ignoring the volume of the payload, find the volume of the baloon in units of m^3.

Other data given: Air density is 1.29 kg/m^3, helium plus air density in the balloon is 0.466 kg/m^3, and helium density is 0.179 kg/m^3.

2006-11-20 04:41:40 · 1 answers · asked by Dee 4

If I could arrange a water turbine so that it would pump 10% of the water driving it back upstream,now the stream has increased by 10% so my turbine can now pump harder and can pump 10% more water back upstream. You see where I'm going? I know you cannot lift yourself up by your bootlaces. So what happens to my turbine?

2006-11-20 04:32:26 · 3 answers · asked by bo nidle 4

Lets say we could attach one end of a piezoelectric substance to a musical tuning fork and the other to a fixed point, then we made the fork vibrate, it would make a voltage come out the piezo substance as a force is being applied.
How much energy could be harvested from this (in Watts)? Lets all assume that the fork is vibrating at 440Hz (the first A above middle C in the musical scale).

2006-11-20 04:20:49 · 6 answers · asked by MacKniven 3

What is the end result of those balloons

2006-11-20 03:53:00 · 17 answers · asked by gideon d 1

#1)In serving, a tennis player accelerates a 56kg tennis ball horizontally from rest to a speed of 30m/s. Assuming that the acceleration is uniform when the racquet force is applied over a distance of 0.5m, what is the magnitude of the force exerted on the ball by the racquet?

#2.)The coefficients of static and kinetic friction between a 50kg box and a horizontal surface are 0.500 and 0.400,respectively.
a.) What is the acceleration of the object if a 250N horizontal force is applied to the box?
b.) What is the acceleration if the 250N force is applied at an angle of 45 degrees above the horizontal?

#3.)A lawnmower is being pushed on a level lawn with a constant force of 200N at an angle of 30degrees downward from the horizontal. How far does the student push the mower in doing 1.44*10^3 Joules of work?

#4.)What is the maximum height reached by a 0.300 kg ball thrown vertically upward with an initial speed of 10.0m/s?

2006-11-20 03:50:42 · 1 answers · asked by Anonymous

I need some physics help on where/why these numbers come out the way they do. I know that gravity is ~9.81 m/s/s and in feet that is about 32 ft/s/s. In math when we talk about vertical motion problems we use the equation d=rt-5t^2 for measuring in meters and we use d=rt-16t^2 for measuring in feet. MY QUESTION is WHY are we basically dividing by 2 from ~10 to 5 and ~32 to 16???

2006-11-20 03:45:47 · 6 answers · asked by smokskleine 1

Did Newton know about that but refused to elaborate an explanation?

2006-11-20 03:43:29 · 1 answers · asked by goring 6

2006-11-20 03:21:48 · 2 answers · asked by goring 6

A uniform solid disk with a mass of 32.3 kg and a radius of 0.264 m is free to rotate about a frictionless axle. Forces of 90.0 N and 125 N are applied to the disk.
(a) What is the net torque produced by the two forces? (Assume counterclockwise is the positive direction.)

(b) What is the angular acceleration of the disk?

2006-11-20 03:17:01 · 1 answers · asked by Jim E 1

2006-11-20 03:16:35 · 6 answers · asked by bryantboy32 2

A CD has a mass of 17 g and a radius of 6.0 cm. When inserted into a player, the CD starts from rest and accelerates to an angular velocity of 23 rad/s in 0.86 s. Assuming the CD is a uniform solid disk, determine the net torque acting on it.

2006-11-20 03:15:53 · 1 answers · asked by Jim E 1

A hiker, who weighs 915 N, is strolling through the woods and crosses a small horizontal bridge. The bridge is uniform, weighs 4055 N, and rests on two concrete supports, one at each end. He stops one-fifth of the way along the bridge. What is the magnitude of the force that a concrete support exerts on the bridge at each end?
(a) near end

(b) far end

2006-11-20 03:14:58 · 2 answers · asked by Jim E 1

another monday morning thinker

2006-11-20 03:13:47 · 8 answers · asked by Anonymous

2006-11-20 03:10:26 · 7 answers · asked by Anonymous

2006-11-20 02:58:04 · 5 answers · asked by SKITTLE 2

What is the frequency of the oscillation of the mass "2m" ?

2006-11-20 02:51:13 · 5 answers · asked by sailordragonball 2

Atom bomb explosion.

2006-11-20 02:49:17 · 8 answers · asked by UNKNOWN TALENT 1

2006-11-20 02:13:50 · 9 answers · asked by mallika r 1

Mine is an octagon, they are symetrical but have many sides.

2006-11-20 02:07:57 · 19 answers · asked by Spoonraker 3

I've read some answers on here that mention that clocks on the top floor of a skyscraper will run faster than those on the ground floor due to less gravity.

Is there any truth in this? It sounds more like an urban myth.

2006-11-20 02:00:24 · 9 answers · asked by Anonymous

2006-11-20 01:57:46 · 8 answers · asked by akhtar 1

2006-11-20 01:43:40 · 2 answers · asked by aliimran2000 1

Why "infinite length" and "negligible circular cross section" is used in the definition of Ampere's law?

2006-11-20 01:03:12 · 1 answers · asked by star123 2

2006-11-20 01:01:33 · 3 answers · asked by gaurav g 1

2006-11-20 00:58:26 · 3 answers · asked by Robert A 1

Why non-conductive substance is used between the plates of capacitor?Tell me reasons.

2006-11-20 00:35:25 · 4 answers · asked by star123 2

If there are = amounts of matter and anti matter in the universe then why after the big bang did some matter get 'left over' i.e why didn't everything completly anhilate into photons ?

Also atoms are made up of =parts of protons and anti protons why do they not anhilite ?

2006-11-20 00:23:27 · 5 answers · asked by Haydn 4

pls give me 3-5 examples, thanks!!!

2006-11-20 00:06:32 · 1 answers · asked by sapphira 1

if so why if not why?.

2006-11-20 00:06:20 · 19 answers · asked by Anonymous

I read today in teh emtro newspaper that some scientists have built a £5billion machine that will split a proton next year and they don't know what will happen, it could create an instant shower of black holes though. Isn't there a way we can stop them and aren't there millions of things the money would have been better spent on?

2006-11-20 00:02:03 · 16 answers · asked by Sarah C 2