Physics - August 2007

when a piece of metal acted on by a force of 25 pounds moves 5 feet to the left he work done is?

2007-08-10 10:31:25 · 6 answers · asked by Anonymous

a child with a mass of 50kg is at rest on a skateboard with a mass of 5 kg the child jumps off the skateboard and the skateboard moves away at 10m/s. the child moves the other direction at?

2007-08-10 10:30:21 · 1 answers · asked by Anonymous

a. Eye Surgery
b. Dvd Player
c. Bar Code Reader
d. Flourescent Light

2007-08-10 10:28:46 · 9 answers · asked by chato r 1

I'd like to find out how much ice it would take to lower the temp of the water in my pool from 92 degrees to 82 degrees. My pool is approximately 13,500 gallons.

2007-08-10 09:47:52 · 4 answers · asked by John R 1

Take a scientist like Enrico Fermi, who was involved with developing the atomic bomb during the Manhattan Project...

All his experiments took place on a university campus where he was a Professor of Physics.

So does that mean those who knew him - colleagues, assistants, students, security guards, etc. - would've addressed him as Professor Fermi? Or Doctor Fermi?

2007-08-10 09:44:58 · 6 answers · asked by nitejrny282 2

A red car is loaded into spring launcher & is launched horizontally. The process is repeated with blue car of greater mass. Both times the spring is compressed the same distance.

which is true?

-the blue has greater KE
-red has greater KE
-both have same KE
-both emerge with same speed
-both have same KE and emerge with same speed

2007-08-10 09:39:23 · 7 answers · asked by bklonging 2

1. A length of wire is cut into five equal pieces. The five pieces are then connected in parallel, with the resulting reistance being 2.00 ohms. WHat was the resistance of the original lenght of wor before it was cut up.

2. An 18.0 ohms, 9.00 ohms and 6.00 ohms resistor are connected in parallel to an emf source. A current of 4.00 A is in the 9.00 ohms resistor.

a. Calculate the equivalnet reistance of the ciruit.
b. What is the potential difference across the source
c. Calculate the current in the other resistors.

2007-08-10 09:15:50 · 4 answers · asked by confused ~ 1

3 rocks of equal mass are thrown with identical speeds are thrown from top of building. X is thrown vertically down, Y is thrown vertically up, Z is thrown horizontally. Assume air resistance is negligible.

2007-08-10 08:49:22 · 12 answers · asked by bklonging 2

If one were able to remove all friction, save for gravity, needed for the design i have in mind, could the machine work?

If friction is removed entirely, why couldn't it work?

2007-08-10 08:06:38 · 8 answers · asked by Jake 1

The police are investigating an accident. They have determined that the mass of car A is 2275kg and the mass of car B is 1525kg. From the skid marks and date for the friction btw tires and concerte, the police determined that the cars, when they were locked together, had a velocity of 31km/h at angle of 43 degrees north of the eastbound street. If the speed limit was 35km/h on both streets, should one or both cars be ticketed for speeding?

2007-08-10 07:26:30 · 1 answers · asked by nick_zz 1

For example, in these pictures:
http://zvis.com/nuclear/dimg.php3?climax1,upkclimax
http://zvis.com/nuclear/dimg.php3?annie,upkannie

Or this video (2 min)
http://youtube.com/watch?v=non1QFZVE6w&mode=related&search=

I've notice there are 13 or 14 stripes in some pics.
They are caused by the explosion or they correspond to something else?

2007-08-10 06:24:29 · 4 answers · asked by Anonymous

2007-08-10 06:21:57 · 0 answers · asked by Alexander 6

Can someone point out a procedure for this one? We want to show principle of levitation but not only using simple magnets we would to apply it to something that might make it float too.

^_^

2007-08-10 05:57:30 · 2 answers · asked by Jecko 1

how fast would i go if i coasted down 2nd half of hill startng from rest?

2007-08-10 05:52:45 · 2 answers · asked by e=mc^2 1

An airplane is flying with a speed of 285 km/h at a height of 3500 m above the ground. A parachutist whose mass is 77.6 kg, jumps out of the airplane, opens the parachute immediately and then lands on the ground with a speed of 3.45 m/s. How much energy was dissipated on the parachute by the air friction? The drag constant of the parachute is 64.0 N/(m/s)^2.

I assume you find the total energy lost but I dont know what to do from there

2007-08-10 05:19:54 · 3 answers · asked by Anonymous

1-a matt black surface
2-a polished silver surface

2007-08-10 05:16:14 · 6 answers · asked by Anonymous

I'm pretty sure I use the formula
square root of radius * gravity...but what else am I missing?

2007-08-10 05:00:51 · 1 answers · asked by benzene boy 1

Please I would love to know what it is because I hear people talking about wavelenghts and I would like to know what one is!

2007-08-10 04:37:29 · 4 answers · asked by Anonymous

The earth has a mass of 5.98X10^kg. The average mass of the atoms that make up the Earth is 40u. How many atoms are in the Earth??

(u stand for 10^-6)

Could someone please show me the steps to solving this?? i know what the correct answer is, but ineed to show how to solve for it.

2007-08-10 04:13:17 · 3 answers · asked by sandcastlesinair 1

2007-08-10 03:43:31 · 7 answers · asked by night_train_to_memphis 6

2007-08-10 02:10:28 · 6 answers · asked by shaheer 2

imagine we have something that looks like a ring
if we try to fill nside of the ring with lets very soft clay if we start from inside, clock wise or anti clock wise doesnt matter imagine putting some clay on your finger and rubbing it inside the ring if we do this layers after layers i believe we will never be able to fill the whole ring with clay beacuse we will always have a hole inside the ring.and becuse of the space
could this be true?can you explain a bit

2007-08-10 02:04:23 · 4 answers · asked by Mehran.S 4

Hello,

First, here is the drawing which shows the situation:

http://img409.imageshack.us/my.php?image=33yb6.jpg

So there is a cored cylinder which radius is R and angular velocity is omega. The cylinder is placed in the the corner so the cylinder touches the wall and the ground. Coefficient of friction between the wall and the cylinder is equal to the coefficient of friction between the ground and the cylinder (this friction coefficient is equal to μ). After how many turns the cylinder will stop to rotate?

Thanks in advance.

2007-08-10 00:56:07 · 4 answers · asked by Pythagor 1

2007-08-10 00:31:49 · 4 answers · asked by Sergio 5

2007-08-10 00:16:44 · 3 answers · asked by piyushjain_2000 1

I'm new to the physics course, and these examples are in my text book, but the answers are not given, I'm pretty lost!


An object moves along the x-axis according to x(t) = (300t² - 2.00t + 3.00)m
Determine:
(a) the average speed between t =2.00 s and t = 3.00 s,

(b) the instantaneous speed at t = 2.00 s and t = 3.00 s,

(c) the average acceleration between t = 2.00 s and t = 3.00 s

(d) the instantaneous acceleration at t = 2.00 s
and t = 3.00 s.

Thanks in advance!

2007-08-09 22:58:00 · 1 answers · asked by Sarah W 1

Hello,
is the following statement true or not ? (not the grammer)

"the energy transfer between a system and the surrendings can only be done by heat, work and mass transfer"...

if I say this, can someone exploit with the question of what if ...?

thanks...

2007-08-09 21:24:51 · 2 answers · asked by Enis T 2

A car in motion is subject to anumber of forces. In particular, it usually experiences a motive force. I also experiences a drag force which is due to the effect of both friction and air drag.

Suggest why as the speed of the car is increased, the maximum motive force increases to a maximum at about 30ms^-1(for this car model) and then decreases after that speed.

2007-08-09 19:47:03 · 3 answers · asked by Anonymous

2007-08-09 19:09:51 · 3 answers · asked by muhammad.kashif 2

When I drop a ball and it hits the ground, it's going to bounce because for every reaction there is an equal but opposite reaction. So the force of the ball coming back to me should be of the same force I dropped it, right? So now I'm confused as to why the ball doesn't bounce forever? Since the ball should be bouncing up with equal force and then falling again. It's like an endless loop. Obviously, this doesn't happen in real life, why?

2007-08-09 18:35:33 · 10 answers · asked by Anonymous