Physics - November 2007

Two billiard balls of equal mass undergo a perfectly head-on collision. If one's ball initial speed was 2.00 m/s and the other's was 3.00 m/s in the opposite direction, what will be their speeds after the collision?

2007-11-14 05:06:52 · 4 answers · asked by Rasheena E 1

A simple pendulum consists of 3.1 kg point mass hanging at the end of 2.0 m long light string that is connected to a pivot point.
Calculate the magnitude of torque, due to the force of gravity, around this pivot point when the string makes a 2.8degree angle with the vertical. Accleleration of gravity is 9.81 m/s^2. Answer in units of N m.

What would the calculation be for a 19.9degree angle? Answer in units of N m.

2007-11-14 05:03:23 · 3 answers · asked by Anonymous

Any info. explaining special relativity would be great, thanks.

2007-11-14 04:57:53 · 6 answers · asked by kano7_1985 4

2007-11-14 04:06:56 · 2 answers · asked by OmegaAsh 1

(a) How much work does an elevator motor do to lift a 920 kg elevator a height of 84 m?
J
(b) How much power must the motor supply to do this in 44 s at constant speed?
W

2007-11-14 04:06:28 · 1 answers · asked by Jim E 1

2007-11-14 04:02:35 · 4 answers · asked by Anonymous

A railroad diesel engine weighs four times as much as a freight car. If the diesel engine coasts at 13 km/h into a freight car that is at rest, how fast do the two coast after they couple?

2007-11-14 03:58:06 · 3 answers · asked by jrasta360 2

2007-11-14 03:47:21 · 3 answers · asked by ღ♥eyeღℓash♥ღ 4

2007-11-14 03:31:05 · 9 answers · asked by Anonymous

Because the water on the north side it goes counterclock wise, but on the south it goes clockwise..
So what happens if you are stuck in the middle?

2007-11-14 02:59:03 · 22 answers · asked by Anonymous

A string has a linear density of 6.40 10-3 kg/m and is under a tension of 280 N. The string is 1.9 m long, is fixed at both ends, and is vibrating in the standing wave pattern shown below in the drawing.

(a) Determine the speed of the traveling wave.
m/s

(b) Determine the wavelength of the traveling wave.
m

(c) Determine the frequency of the traveling wave.
Hz

http://img136.imageshack.us/img136/3117/p1729xj0.gif

2007-11-14 02:54:17 · 2 answers · asked by Jeff 4

The mass of a string is 3.30 10-3 kg, and it is stretched so the tension in it is 110 N. A transverse wave traveling on this string has a frequency of 260 Hz and a wavelength of 0.60 m. What is the length of the string?

2007-11-14 02:52:16 · 1 answers · asked by Jeff 4

The drawing shows two graphs that represent a transverse wave on a string. The wave is moving in the +x direction. Using the information contained in these graphs, write the mathematical expression (similar to Equation 16.3 or 16.4) for the wave. (Answer in terms of t and x. Assume standard units.)

y= ?

http://img134.imageshack.us/img134/8081/1626altli8.gif

2007-11-14 02:44:30 · 1 answers · asked by Anonymous

What is heavy water how does it siffer from tap water, what is its mol wt what is its formula what is it used for?

2007-11-14 02:39:28 · 13 answers · asked by Peter T 2

How can there be smallest distance for space?

Do you think this is just a mathmatical "trick" in order for physicists to fit all the pieces together in their theory of "everything"?

String theory seems to have a lot of mathmatical necessities that seems to be just contrived in order to fit all the pieces together.

It's more a philosophy than science!

2007-11-14 02:02:54 · 4 answers · asked by Anonymous

A pendulum of length L1 has a period T1 = 0.850 s. The length of the pendulum is adjusted to a new value L2 such that T2 = 1.50 s. What is the ratio L2/L1?

2007-11-14 01:32:26 · 1 answers · asked by colin.muller 1

Compressive strength of our bones is important in everyday life. Young's modulus for bone is about 1.4 x 10^10 Pa. Bone can take only about a 1% change in its length before fracturing.

a) What is the maximum force that can be applied to a bone whose minimum cross-sectional area is 3 cm^2? (This is approximately the cross-sectional area of a tibia, or shin bone, at its narrowest point.)

b) Estimate the maximum height from which a 70 kg man could jump and not fracture the tibia. Take the time between when he first touches the floor and when he has stopped to be 0.03 s, and assume that the stress is distributed equally between his legs.

Thanks for the help!!!

2007-11-14 01:25:37 · 2 answers · asked by zoro-kun 2

Chicken Manure
Moisture Content = 70%
N dry Weight basis = 60%
C:N ratio = 10:1

Sawdust
Moisture Content = 35%
N dry Weight basis = 0.11%
C:N ratio = 500:1

If you can help with this problem, could you please explain how you solved it, cheers for the help.

2007-11-14 00:37:13 · 1 answers · asked by Drake 1

I'm an amateur cosmologist/quantum physics enthusiast.

Are there any good recent books on either subjects that's "readable" by a non-mathmatician?

I have read books such as Fabrics of the Cosmos, Parallel Worlds, Infinite Universe, etc.

Thanks

2007-11-13 23:57:59 · 1 answers · asked by Anonymous

When the body requires an increased blood flow rate in a particular organ or muscle it can accomplish this by increasing the diameter of arterioles in that area. This is referred to as vasodilation. What percentage increase in the diamter of an arteriole is required to double the volume flow rate of blood, all other factors remaining the same?

2007-11-13 22:29:05 · 1 answers · asked by Anonymous

A physics professor is pushed up a ramp inclined upward at an angle theta above the horizontal as he sits in his desk chair that slides on frictionless rollers. The combined mass of the professor and chair is m. He is pushed a distance x along the incline by a group of students who together exert a constant horizontal force of F. The professor's speed at the bottom of the ramp is v.

Use the work-energy theorem to find his speed at the top of the ramp.

I know W=K2-K1 and K=.5mv'2 but i dont understand

would it be K= .5mv'2 sin(theta)

I also know F=-kx but how would i equate that for this problem/

please help!

2007-11-13 19:04:51 · 2 answers · asked by Anonymous

2007-11-13 18:59:56 · 2 answers · asked by Anonymous

that collapse upon impact. What is the advantage of this new design?

2007-11-13 18:50:09 · 8 answers · asked by Hu-Li X 1

2007-11-13 18:47:38 · 13 answers · asked by Hu-Li X 1

Is the wavelength or velocity changed?

I think the frequency will change but I don't think the wavelength or velocity will.

2007-11-13 18:37:56 · 1 answers · asked by JQ 9 2

if...
A) the 10-watt bulb is 2 times further away than the 40-watt bulb
B) the 10-watt bulb is 4 times further away than the 40-watt bulb
C)the 40-watt bulb is 2 times further away than the 10-watt bulb
D) the 40-watt is 4 times further away than the 10-watt bulb
E) the 40-watt bulb is 8 times further away than the 10-watt bulb

2007-11-13 16:20:16 · 5 answers · asked by webb_ar 1

This is the question:

A driver traveling east on a dirt road when he spots a pothole ahead. He slows his car from 14 m/s to 5.5 m/s in 6 sec. What is the car's decelaration?

i need to know what the formula is for deceleration!?

2007-11-13 16:16:18 · 4 answers · asked by babyshade94 1

A child in a boat throws a 5.80 kg package out horizontally with a speed of 12.0 m/s. Calculate the velocity of the boat immediately after, assuming it was initially at rest. The mass of the child is 27.0 kg and that of the boat is 45.0 kg.
Magnitude

2007-11-13 16:03:09 · 2 answers · asked by Anonymous

2007-11-13 15:37:40 · 2 answers · asked by WOMBAT, Manliness Expert 7

Mastering Physics frustrates me in that I finish all the problems except for one or two and those just sit there as I try until my tries run out.
Id like help on this problem. You dont need to do it for me, just point me in the right direction.
Jane makes a siphon to mix a drink with 7/8 orange juice and 1/8 cranberry from two identical glasses; one w/ cranberry one w/ OJ
The glass containing cranberry juice has a very large diameter with respect to the diameter of the straw and that the cross-sectional area of the straw is the same at all points. Atmospheric pressure is Pa and the cranberry juice has negligible viscosity.
Consider the end of the straw from which the cranberry juice is flowing into the glass containing orange juice, and let h_o be the distance below the surface of cranberry juice at which that end of the straw is located. Whats the initial velocity in g and h_o of the cranberry juice as it flows out of the straw? g is the magnitude of acceleration due to gravity.

2007-11-13 15:35:31 · 2 answers · asked by leah 1