Physics - April 2007

2007-04-23 03:13:08 · 2 answers · asked by smiley 2

A uniform rod of mass 1.1 kg and length 46 cm is constrained to rotate on an axis about its center. An unknown uniform torque is applied to the rod as it rotates through .28 radians from rest, which requires .8 seconds. The applied torque is then removed and, coasting only under the influence of friction, the rod comes to rest after rotating through 1.6 radians, which requires 5 seconds.
• Determine the angular acceleration of the moving rod before and after the torque is applied.
• Determine the net torque for each phase of the motion.
• What is the applied torque?
• How much work is done by the net torque, by the applied torque and by friction during the first phase of motion?

2007-04-23 02:01:22 · 1 answers · asked by tan 1

A disk of negligible mass and radius 21 cm is constrained to rotate on a frictionless axis about its center. On the disk are mounted masses of 15 grams at a distance of 16.8 cm from the center, 16 grams data distance of 9.87 cm from the center and 38 grams at a distance of 7.98 cm from the center. A uniform force of .7981 Newtons is applied at the rim of the disk in a direction tangent to the disk.
• What will be the angular acceleration of the disk?
• If the force is applied for 7 seconds with the disk initially at rest, what angular velocity with the disk attain?
• What then will be the speed of each of the masses?
• What will be their total kinetic energy?
• Compare the total kinetic energy to the change in the quantity .5 I `omega^2.

2007-04-23 01:52:57 · 1 answers · asked by tan 1

A block of mass 220 grams is held stationary on a level tabletop.
• A mass of 43.9 grams is attached to the block by a string over which runs horizontally fromt the block to a pulley located at the edge of the table; the mass hangs freely from the string over the pulley.
• The frictional force on the block is .044 times the normal force between block and table.
• When the block is released, what will be its acceleration?
• Sketch and label a reasonable facsimile of a scaled diagram showing the forces acting on the block.

2007-04-23 01:44:05 · 1 answers · asked by Joe 1

2007-04-23 01:16:17 · 3 answers · asked by shafqat b 1

2007-04-23 01:13:58 · 2 answers · asked by shafqat b 1

2007-04-23 01:06:47 · 2 answers · asked by mrsjoshgroban 1

2007-04-22 23:46:49 · 1 answers · asked by Anonymous

I was a physicist. but i think i am no a physicist. I am an ant in the physics world that it climbs Einstein !!!

2007-04-22 23:33:15 · 1 answers · asked by a friend 1

20,000 Hz, (b) What is the walelength of a 10-MHz ultrasonic wave?

2007-04-22 23:27:58 · 1 answers · asked by Anonymous

2007-04-22 21:56:03 · 9 answers · asked by Anonymous

2007-04-22 20:50:26 · 5 answers · asked by 3.141592653589793238462643383279 3

What characteristics would the "expanded" atom have? Distance from protron and electron? Electerical potentials(voltage) that these particles would have? Weight and mass?
Angular velocity? etc......

2007-04-22 20:11:25 · 2 answers · asked by Anonymous

2007-04-22 19:13:17 · 5 answers · asked by Anonymous

How do you make gray from the visible spectrum. The teacher in my school taught us that light reflects specific colors which is red, orange, yellow, green, blue, indigo and violet on an object. And the color reflected would be shown. So if only red gets reflected and the rest of the colors gets absorbed, the object would be red. So how would you see gray? This question is really confusing can someone please explain.

2007-04-22 19:06:19 · 3 answers · asked by imnbvcx2005 1

2007-04-22 18:58:23 · 6 answers · asked by Anonymous

affect rate of evaporation of the liquid?

Temperature of the liquid, Surface area, Specific latent heat of vaporisationm, Mass of liquid.

2007-04-22 18:54:10 · 2 answers · asked by 11111111111111111111111111111111 1

A. the force exerted on unit positive charge placed at that point.
B. the force per unit positive charge on a small test charge placed at that point.
C. the work done on unit positive charge to move the charge to that point from infinity.
D. the work done per unit positive charge to move a small test charge to that point from infinity.

2007-04-22 18:43:41 · 6 answers · asked by Anonymous

hi frnds advice me a make up for dusky complexion!!like what kind of lip colours eye colours and nail paints should be preferred!!

2007-04-22 18:42:02 · 3 answers · asked by Anonymous

my answer to this question is
it cannot be predicted when a particular nucleus will decay.
is this correct?

2007-04-22 18:39:28 · 1 answers · asked by Anonymous

I am given a graph (Potential difference (voltage) vs Current (A)) for a resistor. It asks me to use the graph to determine the best value for the resistance. Does this just mean the smallest value I get using R=V/I ?
im assuming the best resistence would be the smallest number.

2007-04-22 18:05:22 · 3 answers · asked by spiffy_mcbang13 1

Imagine Young's double slit experiment:

Light waves screen
>>>>>>> l l
>>>>>>> slit1 l
>>>>>>> l l
>>>>>>> l l
>>>>>>> slit 2 l
>>>>>>> l l
l l


How would the interference pattern differ if this experiemtn was carrie dout in water?

2007-04-22 17:54:55 · 3 answers · asked by EGGO 2

A graph represents the relationship between mass and its energy equivalent.

The slope of the graph represents

1 the electrostatic constant
2 gravitational field strength
3 the speed of light squared
4 Planck's constant

2007-04-22 17:41:45 · 1 answers · asked by xxshootingstarxx 1

A door has a height of 2.1 m along a y axis that extends vertically upward and a width of 0.99 m along an x axis that extends outward from the hinged edge of the door. A hinge 0.30 m from the top a hinge 0.30 m from the bottom each support half the door's mass which is 23 kg.

What is force on door at top hinge?
(N i + Nj)???

What is force on door at bottom hinge?
(Ni + Nj)

2007-04-22 17:35:55 · 1 answers · asked by Anonymous

In the radiator, described in the above question, uses forced convection. Calculate the heat given out by the radiator using natural convection. Use the same dimensions for the radiator and the natural coefficient (2.0)

2007-04-22 17:12:55 · 1 answers · asked by Hammad A 1

please show all work so i can see how u got the answer, thanks :)

1. A train is accelerating at a rate of 2.0 km/hr/sec. If its initial velocity is 20 km/hr, what is its velocity after 30 seconds???

i got 80 km/hr is that correct?

2. A runner achieves a velocity of 11.1 m/s 9 seconds after he begins.
what is his acceleration??

i think the formula is

acceleration= initial velocity - final velocity
--------------------------------
time

2007-04-22 16:38:24 · 3 answers · asked by :) 5

I am looking for activities dealing with solids and liquids that i can do with third graders any ideas will help

2007-04-22 15:51:27 · 5 answers · asked by chicanatx 2

2007-04-22 15:48:28 · 3 answers · asked by Joseph 2

2007-04-22 15:40:59 · 1 answers · asked by Edwin C 2

I mean doesn't a mirror need light to reflect?
yeah, I know... its deep.

2007-04-22 15:34:08 · 11 answers · asked by artsydyl 2