Physics - March 2007

water fills a glass, yet at some point it will spill over. just before that point, the water is actually above the rim of the glass... what is this called?

2007-03-21 17:10:09 · 8 answers · asked by vampguy 1

2007-03-21 16:58:35 · 8 answers · asked by pec_civil98 1

My physics teacher told me that when we approach it, 3 things happen:
1) Your mass approaches infinity
2) Your width approaches 0
3) Time approaches 0
But how does this all work?

2007-03-21 16:47:11 · 11 answers · asked by Anonymous

A man lifts a 5 kg crate from the floor to a shelf (9 m high) at constant speed*.
(*Neglect the very start and very end of the lift, where the crate would of course need to be accelerated from/to rest.)

a.) What is the work done by the man on the crate? J
b.) What is the work done by gravity on the crate? J
c.) What is the net work done on the crate? J
d.) Since the crate is lifted at constant speed, what should the change in its KE be? Is this confirmed by part c?
441 J

2007-03-21 16:37:16 · 2 answers · asked by soccerjock 2

Two balls, of masses mA = 24 g and mB = 76 g are suspended as shown in Figure 7-44. The lighter ball is pulled away to a 60° angle with the vertical and released. Length of string is 30 cm.

What is the velocity of Ball B after collision.

The velocity of Ball A before collision is 1.71.
Va=square root of 2(Distance X g X D cos(angle) X gravity)
=1.71
Velocity of Ball A after collision -.8892.
Ma-Mb divided by Ma+Mb x 1.71
=-.8892

Again we are looking for:

What is the velocity of Ball B after collision.

2007-03-21 16:27:08 · 1 answers · asked by Jessie L 2

Assume: The bullet penetrates into the block and stops due to its friction with the block. The compound system of the block plus the bullet rises to a height of 10 cm along a circular arc with a 18 cm radius.

Assume: The entire track is frictionless. A bullet with a m1 = 30 g mass is fired horizontally into a block of wood with m2 =
4.8 kg mass.

The acceleration of gravity is 9.8 m/s^2.

Calculate the total energy of the composite system at any time after the collision. Answer in units of J.

Taking the same parameter values as those in Part 1, determine the initial velocity of the bullet. Answer in units of m/s.

2007-03-21 16:18:06 · 1 answers · asked by mansun15 1

If 200 g of water at 100 degrees C are mixed with 300 g of water at 50 degrees C in a completely insulated container what is the final equilibrium temperature.

I would like to know the formula and any thing else need to solve this problem. Maybe an example.

Thanks Much

2007-03-21 16:09:07 · 1 answers · asked by mikefredrichpc 1

A 300m long lossless tranmission line has a characteristic impedance of 75 ohm and a phase velocity of 220000km/s at the operating frequency of 3MHz.The line is terminated in an impedance of 150+J40Ohm.If the voltage across the receiving end is 50 V(rms) , determine the current through the load and the voltage input to the transmission line.

2007-03-21 15:46:45 · 1 answers · asked by maake_naki 1

i know that you probably can't light it conventionally with a flame since space has no air, but what would happen if you lit it? would it travel at all?

2007-03-21 15:26:42 · 10 answers · asked by Anonymous

when you look at the reflection of the candle from directly over the flame you see one image but when the viewing angle is shifted a double image is seen. Why?

2007-03-21 14:56:07 · 1 answers · asked by Anonymous

particles of charge +75,+48 and -85 uC are placed in a line. The center one is 0.35m from each of the others. Calculate the net force on each charge due to the other two.
I actually have the solution, but i dont know where they get r=12, r=23 and r=13? and that "r" part is what i dont understand
PLEASE HELP !

2007-03-21 14:49:51 · 1 answers · asked by Linda 1

i'm sure its an obvious explantaion.

the same thing happens if you (don't do it kids) put a crisp packet in the microwave for about 1-2 seconds.

or heat cling film etc etc

2007-03-21 14:46:16 · 30 answers · asked by Sam H 1

if you have a metal plate, or sheet of metal, and a similar wire (ie same material) what are the differences in terms of conduction, resistance, temperature rise etc.

I know that if "use a proportionately larger conductor. For example, using a #4 wire (suitable for 60 A at 90 C rise) [instead of a #10] to handle 15 A will result in an observed rise of approximately 22 C. Basically, doubling the conductor size is required to obtain a temperature rise of 25 percent of the original choice", and was simply wondering the effects of a similar experiment, except comparing a wire with a plate/sheet.

if that makes sense!

2007-03-21 14:44:00 · 5 answers · asked by Sam H 1

A solid sphere of mass 0.6 kg rolls without slipping along a horizontal surface with a translational speed of 5.22 m/s. It comes to an incline that makes an angle of 33 with the horizontal surface. Neglecting energy losses due to friction,

a) what is the total energy of the rolling sphere?

(b) to what vertical height above the horizontal surface does the sphere rise on the incline?

2007-03-21 14:29:39 · 2 answers · asked by Anonymous

How do the magnitudes of the applied force and the frictional force compare to each other for a toy duck waddling across a floor at a constant speed?

2007-03-21 14:17:09 · 1 answers · asked by ogunro a 2

I know how hot air balloons float- its how they change direction that puzzles me, as in how they go one way or another opposed to just where the wind blows them.

2007-03-21 13:57:16 · 4 answers · asked by bluesclues 2

I was messing around with some water ice and salt and then I start to slowly poor the water out of the cup. The water just slid around the glass. I was kinda a first timer here so yeah. This could be like a 1st grade question.

2007-03-21 13:53:12 · 3 answers · asked by Sk8terMov 2

In an Olympic fihure skating event, a 65 kg male skater pushes a 45 kg female skater, causing her to accelerate at a rate of 2.0 m/s^2. At what rate will the male skater accelerate ? What is the direction of his acceleration? I know this questions deals with Newtons laws but I cannot figure out what to do to find the answer? Please help.

2007-03-21 13:29:34 · 3 answers · asked by Anonymous

Helpppppppppppppppppppppp...
the resistance of a metallic wire conductor is inversely proportional to its
lenght
tensile
cross sectional area
temperature

how much work is done in moving 6 electrons through a potetial diffrence of 2 volts
6ev
2ev
3ev
12ev

2007-03-21 13:26:06 · 2 answers · asked by y 1

2007-03-21 13:22:52 · 2 answers · asked by vahan m 1

how can i use refractin in sentence and please give specific answers not " u just did"?

2007-03-21 13:17:33 · 3 answers · asked by ? 3

2007-03-21 13:10:58 · 1 answers · asked by Tem 1

In other words, from thousands of feet up. I thought I heard about something like that but it may not be true. Any documentation on the web?

2007-03-21 13:01:50 · 11 answers · asked by Anonymous

DiS 4 M3 SCi3NC3 H0M3W0RK

2007-03-21 13:01:23 · 7 answers · asked by B5_BRyAN WiF3Y 1

1) In order for you to walk, your body has to change the chemical energy of food into what other kind of energy?
2) When the body temperature goes up, the chemicals energy of food has been tranformed into what other kind of energy?

2007-03-21 12:56:58 · 2 answers · asked by Anonymous

1. The air temperature is 20 degree celcius. You are swimming underwater when when you hear a boat noise. Then, 3.5s later, you hear a crash. If the speed of sound in water is 1450 m/s, how long after the crash does your friend on the dock beside you hear the crash?

2007-03-21 12:46:14 · 1 answers · asked by no name 1

Can you explain this to me as best you can or tell me a good place where I can get information on this.

2007-03-21 12:36:20 · 10 answers · asked by Anonymous

2007-03-21 12:31:34 · 1 answers · asked by Anonymous

2007-03-21 12:27:23 · 1 answers · asked by Crystal D 1

Please help me figure this out. My light bulb is 20Watt. I use the light bulb for 10 hours. Con Edison charges $0.13 per KWHR (kilowatt per hour). how much is the bill?

2007-03-21 12:22:13 · 2 answers · asked by Anonymous