Physics - March 2007

There is a certain kind of rope which takes exactly one hour to burn from end to end. The rope is not uniform, not symmetric - thicknesses throughout its length vary randomly. No two such ropes will be identical.
You have two such ropes. How will you measure 45 minutes?

2007-03-09 20:08:35 · 1 answers · asked by Anonymous

a shoe is dropped into a lake from 20 ft above the lake surface. upon hitting the water the speed of the shoe is reduced by half and the shoe then sinks at constant speed. if it reaches the bottom 4 seconds after it was dropped, how deep is the lake?

2007-03-09 18:47:51 · 5 answers · asked by princess 1

A 1.0 kg hollow ball with a radius of 0.10 m is filled with air and is released from rest at the bottom of a 2.0 m deep pool of water. How high above the water does the ball rise? Disregard friction and the ball’s motion when it is only partially submerged.

2007-03-09 17:52:56 · 6 answers · asked by Amiraan 4

i am conducting an investigatory project in physics regarding the use of the sap of a certain tree or plant as a substitute or the fluid used in lighters. Now, i don't know what tree or plant that can be found in the Philippines, particularly in Luzon, has a flammable sap.

2007-03-09 17:25:33 · 1 answers · asked by jam_mka 2

A football game is proceeding. On the football the two teems A and B apply equal force and pressure. Then why does one team loses while the other wins?

2007-03-09 17:15:23 · 16 answers · asked by splendid_suryansh 2

I need specific websites. (any James bond movies)

2007-03-09 17:03:33 · 3 answers · asked by historyman 1

i heard that we have an average of 50k ohms of resistance i want to know what else because we are making a circuit in a computer program and our circuit needs to be touch by hand to function but we cant simulate it because we dont know what can replace the human plzzz help

2007-03-09 16:44:58 · 3 answers · asked by arn_14 2

A ball of mass 10.3 g with a speed of 20.4 m/s strikes a wall at an angle 17.0o and then rebounds with the same speed and angle. It is in contact with the wall for 42.0 ms. What is the magnitude of the impulse associated with the collision force?

the wall is vertical if it makes a difference

2007-03-09 16:35:16 · 3 answers · asked by Geoff M 1

Also, where can I find the graph of energy absorbed by the molecules vs frequency of incident radiation? How do I find its bond strength in terms of physics?

2007-03-09 16:29:50 · 1 answers · asked by I who needs answers 1

2007-03-09 16:02:44 · 11 answers · asked by kamlesh genius 1

I have a 9VDC with two resistors in series. R1 = 3900 ohms, R2 = 100 ohms.both 5% tollerance
Upon testing resistance of each
R1 = 3840 Ohms
R2 = 100 Ohms
Both are still within +/- 5% range
Upon testing my power source is in fact 9.81 volts
Total Resistance is 3930 ohms ( range : 3800 - 4200 )
according to formula current should be 2.5mA, upon test it is in fact 2.5mA.
Voltage Drop ( formula)
R1 = 9.6 Volts
R2 - 0.25 volts
Total 9.85 // is this acceptable since it differs only slightly??
Voltage Drop ( Test)
R1 - 9.38 volts = 9.4 Volts
R2 - 0.24 volts = 0.2 Volts
Total . . . . . . . 9.6 Volts
Are these decrepencies ok and a normal thing?
Battery reads 9.81 Volts, the formula produces 9.85 volts, and actual testing proves it is 9.6 Volts.

Total resistance is 3930 but individual resistances adds to 3940. Should i not worry about this as long as it is still within the tollerance range?

2007-03-09 15:43:21 · 5 answers · asked by Anonymous

would you see. You know the story about the twins, one who travels at high speeds comes home younger than the other twin.
How if the first twin was to observe the twin staying at home wouldn't he see time speed up to account for the age difference when he gets back.
I just listened to a physicals course and the lecturer said in all circumstances when you travel at high speeds you see stationary objects slowed down.

I can't make sense of it...i can't sleep.

2007-03-09 15:42:06 · 9 answers · asked by Anonymous

If E=mc2 is true. why can't it be other way around?!?

2007-03-09 15:38:42 · 4 answers · asked by Anonymous

... ARE THE SAME PROCESSES OCCURING IN THE SUN AND THE REACTORS? EXPLAIN

CAN U GUYS HELP ME ...

2007-03-09 13:32:22 · 11 answers · asked by Anonymous

2007-03-09 13:25:35 · 12 answers · asked by karthikeyan v 2

melts to water at 0 degree Celsius?

2007-03-09 13:16:08 · 2 answers · asked by missea 1

2007-03-09 13:11:59 · 3 answers · asked by missea 1

2007-03-09 13:09:55 · 1 answers · asked by missea 1

2007-03-09 13:07:26 · 4 answers · asked by missea 1

how does Newton's third law relate to bowling?

2007-03-09 12:41:19 · 11 answers · asked by Wes S 1

Nothing is something. There is no such thing as nothing. Before god or evolution there was nothing. Where did that nothing come from.............................

2007-03-09 12:40:11 · 10 answers · asked by Anonymous

do u know anything about this im having trouble solving it ..plzzz help me

2007-03-09 12:39:59 · 21 answers · asked by Anonymous

any answers would be appreciated

2007-03-09 12:14:09 · 7 answers · asked by Wes S 1

Three capacitors (4.0, 6.0, and 8.0 µF) are connected in series across a 50.0-V battery. Find the voltage across the 4.0-µF capacitor.

2007-03-09 12:09:47 · 1 answers · asked by CHI U 3

A 3.0 µF capacitor and a 4.0 µF capacitor are connected in series across a 46.0 V battery. A 13.0 µF capacitor is also connected directly across the battery terminals. Find the total charge that the battery delivers to the capacitors.

2007-03-09 12:09:04 · 2 answers · asked by CHI U 3

If an airplane were traveling 65 in the air at 20,000 feet, would it beat a car traveling the same speed?

To rephrase my question... if I could fly, and I was 100 feet in the air, and my friend was on the ground. If we both took one equal step, who would have travelled a farther distance? me (since i'm high in the air) or did we both travel the same distance???

thanks for helping me,
if you could explain the physics behind this too that would be great!

2007-03-09 11:46:52 · 5 answers · asked by Captain Whiskerboy Litterbox 3

If you attach a string to a ball and begin swinging it around your head, the ball will travel in a cirlce. Lets's suppose that the ball is traveling counterclackwise, as viewed from over head.

A. Although the ball is traveling with a constant speed, it is accelerating. Which was is it accelerating?

B. In which direction is the net force on the ball?

C. Inwhich direction is the ball traveling at the moment the ball passes directly in front of you?

D. If you let go of the string at the moment the ball passes directly in front of you will the ball travel? why?

E. You feel an outward tug on the string, yet there is no outward force on the ball. The only way that the ball can tug on the string is if the string is tugging on the ball. What effect does the string's pull have on the ball if there isn't any outward force on the ball?

2007-03-09 11:46:36 · 1 answers · asked by Yarka 1

The rocket of mass .05 kg is fired at 647 m/s north. Before the rocket is fired, the rocket launcher, which has a mass of 4.65 kg, is also moving north at 2 m/s. What is the velocity of the rocket launcher immediately after the rocket is launched assuming momentum is conserved?

2007-03-09 11:43:33 · 4 answers · asked by Da MC 2

A 4.2 kg object is suspended by a string from
the ceiling of an elevator.
The acceleration of gravity is 9.8 m/s^2 :

Determine the tension in the string if it
is accelerating upward at a rate of 4.9 m/s^2.
Answer in units of N.

Determine the tension in the string if it is
accelerating downward at a rate of 4/9 m/s^2.
Answer in units of N.

2007-03-09 11:28:45 · 1 answers · asked by i.p 1

In Figure P19.21, the cube is 43.0 cm on each edge. Four straight segments of wire -- ab, bc, cd, and da -- form a closed loop that carries a current of I = 4.50 A in the direction shown. A uniform magnetic field of magnitude B = 0.0200 T is in the positive y-direction. Determine the magnitude of the magnetic force on each segment. http://www.webassign.net/sercp/P19-21.gif

ab=___N bc=___N cd=___N da=____N

I think that ab=0N but I'm not sure how to find the others

2007-03-09 11:07:39 · 2 answers · asked by Anonymous