Physics - September 2007

An airport has runways only 194 m long. a small plane must reach a ground speed of 42 m/s before it can become airborne. Whast average acceleration mus the planes engines provide if it is to take off safely from it airport?

2007-09-03 10:36:45 · 4 answers · asked by Tony N 1

The charges and coordinates of two charged particles held fixed in an xy plane are q1 = +2.5 µC, x1 = 4.0 cm, y1 = 0.50 cm, and q2 = -4.0 µC, x2 = -2.0 cm, y2 = 1.5 cm.
(a) Find the magnitude of the electrostatic force on q2.
i got that to be 24.2 N
(b) Find the direction of this force.
° (counterclockwise from the +x axis)
(c) At what coordinates should a third charge q3 = +4.0 µC be placed such that the net electrostatic force on particle 3 due to particles 1 and 2 is zero?

2007-09-03 10:32:51 · 2 answers · asked by Anonymous

You are studying standing sound waves in an organ pipe of length L with both ends open. What wavelengths of sound can exist as standing waves in this pipe? Express your answer in terms of the length L.

For this I had lambda = (3L) / 2. The question also asks for an organ pipe of length L with one end open and one end closed but I don't know (maybe 5L / 2??).

2007-09-03 10:31:16 · 1 answers · asked by Anonymous

A helicopter is ascending vertically 5.5m/s. At a height of 105 above the earth, a package is dropped. How much time does it tkae for the packs to reach the ground?

- And -

Bond is standing on a bridge, 10m above the road below. He spots a flatbed truck loaded with mattreses approaching at 30m/s, which he measures that the telephone poles the truck is passing by are 20m apart. The bed of the truck is 1.5m above the road, and Bond quickly calculates how many poles away the truck should be when he jumps down the bridge onto the truck. How many poles is it?

Please show all work too, I am really confused. Thanks!

2007-09-03 10:30:17 · 1 answers · asked by metro900 3

2007-09-03 10:17:47 · 2 answers · asked by Anonymous

A controlled experiment is one where you subject your hypothisies to a seris of tests while controlling many variables but i need an example

2007-09-03 09:58:26 · 3 answers · asked by Emily G 1

2007-09-03 09:57:41 · 2 answers · asked by X 1

introduction to physical science- scientific inquiry

2007-09-03 09:49:50 · 2 answers · asked by gomarissa 2

1. Jules Verne in 1865 proposed sending men to the Moon by firing a space capsule from a 220-m-long cannon with final speed of 10.97 km/s. What would be the unrealistically large acceleration experience by the space traverlers during the launch.( A human can stand an acceleration of 15g for a short time.)
2. An aircraft has a lift-off speed of 120 km/h. What minimum constant acceleration does this require if the aircraft is to be airborn after a takeoff run of 240m.
3. A train is traveling down a track at 20m/s when the engineer applies the brakes, resulting in an acceleration of -1.0m/s squared as long as the train is in motion. How far does the train move during a 40s interval starting at the instant the brakes were applied?
4. A mailbag is released from a helicopter that is descending steadily at 1.5m/s. After 2.00s, (a) what is the speed of mailbag (b) how fart is it below the helicopter (c) what would be the answers to A and B if the helicopter was going up at speed of 1.5m/s

2007-09-03 09:36:43 · 1 answers · asked by RickySingh2006 2

2007-09-03 09:24:26 · 3 answers · asked by Anonymous

A baseball is seen to pass upward by a window 29 m above the street with a vertical speed of 8 m/s. The ball was thrown from the street.

(a) What was its initial speed?...m/s
(b) What altitude does it reach?....m
(c) How long after it was thrown did it pass the window?....s
(d) After how many more seconds does it reach the street again? ....s

please also explain to me how to do it, i would really appreaciate it ..Thanks :)

2007-09-03 09:18:35 · 2 answers · asked by Nikita 1

On coming to a stop, a car leaves skid marks 92m long on the road. Assuming a decleration of 7.00m/s^2, estimate the speed of the car just before braking.

2007-09-03 09:11:31 · 2 answers · asked by Lizzie 1

...is more disordered than the gas cloud it evolved from?

Sounds backwards to me. (Im trying to understand entropy)

2007-09-03 09:11:27 · 9 answers · asked by Anonymous

2007-09-03 08:32:10 · 3 answers · asked by kyrov 1

Need answer by thursday

2007-09-03 08:23:38 · 2 answers · asked by Tyler N 1

In order to qualify for a racing competition the a racing car must achieve minimum speeds 250km/h on a 1600 m long track. The car travels at 230km/h for the first half of the track, what must be the minimum avg speed of the car during the second half in order to qualify.
Anything will work such as which formula to use and etc.

2007-09-03 07:51:31 · 4 answers · asked by RickySingh2006 2

An electric field in a given region of space is given by E=3.3x2i (in N/C). What is the magnitude of the potential difference between two points x=0 m and x=5.3 m, i.e. |V(x=5.3 m)-V(x=0 m)|?

2007-09-03 06:48:57 · 2 answers · asked by Dita 5

I understand that when we look at distant stars in the night sky we are looking at light that has taken many years to reach us. But does that light and indeed all light have a power source and if so what is it?

2007-09-03 06:00:34 · 15 answers · asked by GRAHAM P 1

My question is concerning astrophysic

2007-09-03 05:40:23 · 10 answers · asked by Mike Fox 1

Electricity can surely kill at certain amperage and voltage which I know. Now this is vice versa.

2007-09-03 05:11:05 · 7 answers · asked by Orlando O 2

Suppose i am travelling on a photon , sitting on it , now as my speed is equal to C , the time gets dilated for me and becomes INFINITE , what does this actually mean ?

Does it means that TIME does not exist for me , no hours, no minutes & no seconds with respect to a stationary observer , but if i have an observer besides me sitting on a photon with a watch which is moving with speed c then the intervals of time will exist for me

2007-09-03 04:00:19 · 6 answers · asked by Devil 4

2007-09-03 03:18:14 · 9 answers · asked by Panji P 1

When the airport sends out a rescue crew, how far should this crew fly to go directly to this plane?

2007-09-03 02:45:06 · 2 answers · asked by J 1

I see no problem with this combination. Since the scientific community has yet to explain the Big Bang Theory, which goes against all know laws of physics...Bodies at rest, tend to stay at rest...so what caused the Big Bang. Then we have the matter of our brain. How could evolution explain the fact that we only use 10% of our brain's capacity? What kind of natural selection could cause this phonomia? With an Intelligent Design all the answers are quit simple. With Intelligent Design time is no longer an issue so it could take billions and billions or years and it wouldn't matter. Have set rules and set back and let them evolve. With Alpha Omega there is no beginning and no end. The whole universe is totally amazing. Let's relax and enjoy it.

2007-09-03 02:25:47 · 15 answers · asked by rett y 1

2007-09-03 02:23:40 · 1 answers · asked by kvsnsrd 1

2007-09-03 02:03:06 · 13 answers · asked by karthikg_92 1

Given the fact that the number of turns and the current in the solenoid affects the strength of the electromagnet, how does the above two factors exactly influence its strength? Can someone give me an answer in terms of electrons?

2007-09-03 01:14:27 · 4 answers · asked by Anonymous

I want to get an answer with a scientifical explanation regarding static electricity

2007-09-03 00:34:41 · 1 answers · asked by Ra@ma_de 1

as opposed to looking at the horizon?

2007-09-02 23:36:22 · 1 answers · asked by Alex 2

What would this be....
[1.80+1.60] *2 ??????
Considering the sigfig rules

2007-09-02 22:33:45 · 2 answers · asked by Anonymous