Physics - October 2006

All I wanna do is re-collimate a diffuse laser reflection...
35 mW of very green laser light shining on a small white plastic object is BRIGHT. The light seems readily-enough gathered with a large objective lens, but I get hung up there time and again.
Should I be using smaller gathering lenses and/or pinhole optics in some way?
Or hell, am I better off trying to gather the light with some sort of convex mirror?

Note: my desired gathered/focused/collimated output does not need to be a tiny beam - in fact, a beam with some surface area is preferable.

Can this be done with standard optics?

2006-10-26 08:38:26 · 3 answers · asked by nowyermessingwithasonofabitch 4

from ground level to the floor above, a vertical height of 4.50 m. What is the work done on the man by (a) the gravitational force and (b) the escalator?

2006-10-26 08:21:05 · 2 answers · asked by meggers 3

the line of motion to reduce the probe's speed. The retrorockets generate a force of 170000 N over a distance of 3400 km. What is the final speed of the probe?

2006-10-26 08:17:48 · 2 answers · asked by meggers 3

2006-10-26 08:13:35 · 5 answers · asked by David K 1

2006-10-26 08:12:30 · 3 answers · asked by Dimitri C 1

Why not? Shouldnt I be able to "print" a document by "photocopying" an empty paper by placing it in front of a computer screen?

2006-10-26 08:07:08 · 4 answers · asked by Anonymous

this is really stupid. our teacher asked us to do this for a 'uniqe' assignment. has anyone done this before?
Please help.

2006-10-26 08:01:36 · 12 answers · asked by Wynand 2

2006-10-26 07:49:52 · 4 answers · asked by Anonymous

2006-10-26 07:34:00 · 3 answers · asked by Nap 1

2006-10-26 07:10:19 · 3 answers · asked by albertomichieli 1

Neither me or a classmate I asked can figure out the answer to a couple of our questions and we can't ask the teacher easily because it is an online course.

Help or answers are appreciated.

Jess, who weighs 50 kg, is riding a 10-kg skateboard. The skateboard and Jess are moving east at 5 m/sec. Jess falls off the skateboard and hits the ground at 4 m/sec east, relative to the ground. Calculate the velocity of the skateboard.

The end of the lever of a tire jack travels 7 m for every centimeter that it lifts the car. If the car has a mass of 1000 kg and a force of 50 N is needed to lift the car, what is the efficiency of the jack?

Thank you

2006-10-26 06:46:46 · 3 answers · asked by Truthitude 1

2006-10-26 06:05:39 · 13 answers · asked by rachna 2

what dose

EM, S, W, G. have in common

EM= Electro-Magnetism

S= Strong nuclear force

W= Week nuclear force

G= gravity

if you can explain it will help me a lot

2006-10-26 06:01:36 · 5 answers · asked by jessey freemen 2

i need to research glass reinforced polymers for my coursework.
so far, i have not been able to find good websites that will answer my questions. if anyone knows any websites or books that i can borrow from the library (that look into composite materials or glass reinforced polymers in detail) or has researched the same,
cud u pls give me the name of the website or the book. i'm desperate. coursework is due in december and i haven't done anything!

2006-10-26 05:52:26 · 3 answers · asked by amandac 3

we have an assumption that when something is immersed in fluid the level of fluid increase. but when the above experiment was done nothing happened

2006-10-26 05:51:20 · 7 answers · asked by salin_i s 1

what the compass go always to north?

2006-10-26 05:23:38 · 6 answers · asked by Anonymous

As Salt concentration of seawater increases, boiling pt increases. however, vapour pressure decreases. how do we calculate the latent heat of evaporation?

2006-10-26 05:06:56 · 3 answers · asked by weiqiang c 1

How u love it

2006-10-26 05:00:06 · 9 answers · asked by good answers bad questions 2

2006-10-26 04:48:30 · 1 answers · asked by Non P 1

Compute the acceleration of a block sliding down a 36 degree incline, the coefficient of sliding friction being 0.17.

2006-10-26 04:43:37 · 5 answers · asked by caaa37 1

from the top of a hill that is 26.0 m high. What is the translational speed of the tire when it reaches the bottom of the hill in units of m/s? Assume acceleration of gravity is 9.81 m/s^2 and that the tire is a hoop with I = mr^2.

2006-10-26 04:38:24 · 1 answers · asked by Dee 4

When you lift a bowling ball with a force of 82N, its upward acceleration is a. If you lift it with a force of 92N, the ball's acceleration is 2a. Find (a) the weight of the bowling ball and (b) the acceleration a.

2006-10-26 04:37:09 · 3 answers · asked by Anonymous

2006-10-26 03:50:24 · 2 answers · asked by rohit_gupta322 2

A horizontal force F of 250 N pushes a block having a mass of 30 kg against a vertical wall. The coefficient of static friction between the wall and the block is 0.5. Will the block start moving?

2006-10-26 03:43:08 · 10 answers · asked by caaa37 1

Hey guys! Please, can you tell me
what is the physics behind direct circuit? Thanks.

2006-10-26 03:07:10 · 6 answers · asked by aprillej28 1

2006-10-26 03:02:29 · 7 answers · asked by Anonymous

Im doing a science project on heat transfer with clothes. anything to do with clothes and how they keep us warm in the winter will help me out.

2006-10-26 02:42:38 · 5 answers · asked by mercedes r 1

If science will believe in something demonstrated by experience, which test should be necessary to prove God?

2006-10-26 02:36:34 · 22 answers · asked by Anonymous

a wave require a medium for its propagation in space there is no medium still how em wave travel through it

2006-10-26 02:33:35 · 6 answers · asked by renjuk4d 1

2006-10-26 02:06:05 · 21 answers · asked by markjohnoneill 1