Physics - November 2007

Since gravity cannot be artificially produced in a lab, does that make gravity still a theory? Just for the record, I know nothing of science.

2007-11-29 14:03:09 · 3 answers · asked by Anonymous

1. Explain why long range cannons have long barrels.


2. A flight attendant and a passenger toss a ball back and forth in a moving airplane. Does the kinetic 9. At what point in its motion is the kinetic energy of a pendulum bob at a maximum? ______ At what point is its potential energy at a maximum? ________ When its kinetic energy is half its maximum value, how much potential energy does it have?

3. A physics instructor demonstrates energy conservation by releasing a heavy pendulum bob and allowing it to swing to and fro. What would happen if in her exuberance, she gave the bob a slight shove as it left her nose? Explain

2007-11-29 14:02:19 · 1 answers · asked by crazymongoose129 2

A water rocket, launched from the ground, rises vertically with acceleration of 30 m/s^2 for 8.7 s when it runs out of "fuel". Disregarding air resistance, how high will the rocket rise?

Steps Please. Thanks =)

2007-11-29 13:40:02 · 1 answers · asked by kickitup21 1

44 grams of water at 16 Degrees C is mixed with 450 grams if ice at -16C. what mass of water freezes? what is the change in entropy of the system? ( The heat capacity of water is 4190 J/Kg , that of ice is 2090 J/Kg, and the heat of fusion of water is 3.34 x 10^5 J/Kg.)

2007-11-29 13:36:26 · 1 answers · asked by Anonymous

2007-11-29 13:15:24 · 4 answers · asked by enamarquez17 1

2007-11-29 13:13:50 · 3 answers · asked by enamarquez17 1

2007-11-29 13:08:49 · 2 answers · asked by Gruntled Employee 6

An astronaut is golfing on the moon, which has gravity of 1.63m/s^2 down. If he hit the ball and it left the tee with an initial velocity of 15m/s at an angle of 26 degrees, how much time does the ball spend in the air? How far does the ball travel from the tee?

2007-11-29 13:08:03 · 1 answers · asked by Keytosuccess 1

when a magnetic is inserted into a coil, does it matter if its North pole of the magnetic or south pole or will the current oppose the magnet ether way?

2007-11-29 13:04:37 · 1 answers · asked by mr.christie 3

A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is:

2007-11-29 13:03:44 · 1 answers · asked by Chris N 1

_ _ _ _ _ _ _ _ _ _ _ _ _ help! Please There goes the words that i need help on

2007-11-29 13:02:39 · 2 answers · asked by delon b 1

i have a huge test that i am trying to prepare for. However there are many problems about Vectors, which i do not get al all. i will give you just a few example of the different kinds of questions, if anyone know how to do any of these please help.. thanks a billion.

oh by the way this isn't my homework its just practice problems that i'd like to learn how to do before my test comes. thanks again.

1.A quantity with both a magnitude and a direction is called a
Scalar
Vector
Number
Unit


2. Vector A has a magnitude of 9 and points due north, vector B has a magnitude of 3 and points due north, and vector C has a magnitude of 5 and points due west. What is the magnitude of the resultant vector A+B+C?
20
13
15
11


3. The components of vectors are considered
Vectors
Scalars
Units
Numbers


4. A person walks 3.0 km northeast, then 1.0 km east, and finally 4.0 km south. Calculate the distance from the starting point to the finishing point of the walk

2007-11-29 13:01:26 · 1 answers · asked by Anonymous

A m1 = 4.00 kg block on a smooth tabletop is attached by a string to a hanging block of mass m2 = 2.50 kg, as shown in Figure 6-29. The blocks are released from rest and allowed to move freely. So m1 is on top of a table and m2 is hanging down from a string. What is acceleration and tension?

2007-11-29 12:55:39 · 2 answers · asked by Anonymous

2007-11-29 12:48:05 · 2 answers · asked by cutiepie123 2

how does the 3rd law of motion has to do with it

2007-11-29 12:38:17 · 2 answers · asked by Anonymous

A 500kg roller coaster car is pulled to the top of a hill 45m high and arrives with a speed of 4m/s.



* How fast will the car go when at a point 29m above ground?

2007-11-29 12:21:20 · 1 answers · asked by johnnyboy 2

An electron passes through a slit of width 6 times 10-8 m. What is the uncertainty in the electron's momentum component in the direction perpendicular to the slit but in the plane containing the slit?

Lost, any help would be great. Thanks

2007-11-29 12:17:17 · 1 answers · asked by Jeff T 1

On a summer afternoon, a smokestack casts an 8-meter shadow. At this time of the day, rays from the sun are striking the ground at an angle of 75 degree. To the nearest tenth of a meter, how high is the smokestack ?

2007-11-29 12:13:03 · 1 answers · asked by erikjjjacob 1

A jogger on a circular track that has a radius of .250 km runs a distance of 1 km. What angular distance does the jogger cover in a) radians and b) degrees?

A great explanation would be very wonderful! Thanks!

2007-11-29 12:12:45 · 5 answers · asked by bee_rice33 1

I did this experiment in class. It was a simple experiment. My teacher had a wooden ramp leaning up against the wall. He had a wooden disk and a metal ring. By ring, I mean it had no inside, just like a ring. By disk, I mean it had an inside to it. Both the wooden disk and the metal ring had the same mass, same diameter, same size and same shape. They were released down the ramp at the same time and the wooden disk always made it down first. My question...Why does the disk always beat the ring? Explain and show a mathematical proof why.

I really have no idea as to why except that there must be a force acting on them?!? I have no clue where to start on the mathematical proof....can someone please help me asap? Thank you tons if you can help.

2007-11-29 11:56:56 · 2 answers · asked by ☺♠JonasJay♫♦ 5

2007-11-29 11:53:07 · 4 answers · asked by mamanoelia 3

Please don't say Einstein. And I need someone that is somewhat interesting

2007-11-29 11:06:27 · 4 answers · asked by Str1pes 2

Water flows over a section of Niagara Falls at the rate of 1.0 x 10^6 kg/s and falls 48.0 m. How much power is generated by the falling water?
_W

2007-11-29 11:04:50 · 1 answers · asked by Anonymous

Alright. Well, we are doing a lab and I need some equations.
Basically, we had to time how fast it took us to run up 4 flights of stairs. (10 Meters Up to Down in a Straight Line)

My time was 12.30. I weigh 105 lbs. My Horsepower was .61 (but negate this, I only need the equations to get to this point using the fact that the staircase was 10m, my time was 12.3, and I weigh 105 lbs)

I need the equations and plug ins to get Horsepower and How many times I'd have to run up the stairs to burn off 140 Calories.

Thanks

2007-11-29 10:47:43 · 2 answers · asked by Anonymous

The E string of a violin has a mass per unit length of 4.0*(10^-4)kg/m, and must be tuned to a frequency of 660 Hertz. The vibrating length of the string is 0.33 m. Calculate the tension when the string is in tune.

2007-11-29 10:45:14 · 2 answers · asked by Gabe 3

If you place an object with a mass of 613kg on an elevator that can generate up to 950 watts of power, what is the constant speed of the elevator lifting the object? (And of course, gravity is 9.8m/s squared)

If you pump water up 92 meters and um... it's going 75 L/s?... each liter has a mass of 1kg, then what is the power (I think? -- watts, anyway) to maintain that 75L/s thing?

Really sorry for being unclear, I had to attempt translating that. :/ Anyway, steps please. Thanks in advance!

2007-11-29 10:44:04 · 2 answers · asked by Ashley 2

1) a person with a mass of 64 kg sits at a distance of 2.7 m from the pivot point, located at ghe middle of a 7.0 m seesaw. how far from the pivot would a person on the other side with a mass of 75 kg have to sit to balance the seesaw?
a. 2. 30 m
b. 3.00 m
c. 3.16 m
d. 3.50 m

2) a 3kg box resting on an incline of 20 degrees, when given a gentle tap, will slide at a constant speed. what is the coefficient of friction between the two surfaces?
a. .30
b. .34
c. .36
d. 1.02

2007-11-29 10:26:33 · 1 answers · asked by Anonymous

Explain.
Plzzz Help

2007-11-29 10:15:25 · 2 answers · asked by Nick 2

2007-11-29 09:56:30 · 1 answers · asked by Anonymous

HELP!

2007-11-29 09:53:54 · 10 answers · asked by Anonymous