Physics - June 2007

2007-06-03 01:19:47 · 2 answers · asked by Anonymous

in simple terms with regards to digital signal processing

2007-06-03 00:58:52 · 6 answers · asked by jadi 2

2007-06-03 00:52:48 · 1 answers · asked by Zephyr 2

what are the applications of friction to everyday life?

2007-06-02 23:59:59 · 3 answers · asked by kairrizordick 1

1 . A 10.0mg sample of strontium-90 is found to have an activity of 24 Bq. Its halrd-life is 28.5 years. Calculate:
a) the fraction of undecayed atoms of Sr-90 remaining after 114years.
b) the activity of the sample after this time.

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2-The radioactive isotope gold-198 is a B- (Beta) emitter and is often used as a radioisotipic tracer. It can be used, for instance, by health engineers to trace the flow of sewage. it is found that its activity drops to 1/8 of its original value in just over 8 days.
a) Write the B-decay equation for this isotope (198 over 79 Au). You will need to refer to a periodic table.
b) Calculate its approximate half-life.
c) Estimate the fraction of gold-198 remaining after 2 weeks.
d) Why do you think gold-198 may be chosen as a tracer to study the flow of sewage?



If you know the answer, plz write it down.. and i really appreciate it! Thanks alot!

2007-06-02 23:55:45 · 2 answers · asked by Scaryhunter 2

If I am given a time and a distance, is there a way of calculating acceleration from just these two values?

I thought acceleration = 2 x (distance / (time)^2)

Any ideas?

2007-06-02 23:49:07 · 6 answers · asked by Anonymous

2007-06-02 23:23:19 · 2 answers · asked by jimy86Leb 2

2007-06-02 22:00:15 · 1 answers · asked by Matz 1

When a microwave filter consisting of vertical parallel metal rods is in the absorbing position, oscillating currents are set up in the rod. At any one instant, the current in each rod has the same magnitude and direction. At that instant:

a. the rods will try to move apart horizontally

b. the rods will try to move together horizontally

c. the rods will try to shift vertically upwards

d. the rods will try to shift vertically downwards

e. the rods will not the affected because the source of current is not a battery

Also

A bar magnet is dropped from above and falls through a loop of wire north pole first. The current in the loop-

a. always flows clockwise

b. always flows counterclockwise

c. the current in the loop flows first in a clockwise, then in a counterclockwise direction

d. the current in the loop flows counterclockwise, then in a clockwise direction

e. no current flows in the loop because both ends of the magnet move through the loop

HELP!!!

2007-06-02 21:21:09 · 1 answers · asked by Anonymous

I need to know how the effects of gravity is beneficial to human beings.

2007-06-02 20:12:40 · 11 answers · asked by Anonymous

i have an onager (kind of catapult) where the variables are supposed to be changed off and so have different affects of where the projectile travels. the first variable is changing the mass of the projectile, it tells me that increasing the mass decreases time and distance travelling. 2nd variable is sling length when having a too short and too long sling the distance and time is decreased but time is increased for a too short sling. 3rd variable is the throwing arm length it shows the longer the arm the longer time and distance. 4th variable is the skein force shows the bigger the skein force the bigger time and distance travelled. Can anyone explain the results given? I am not sure what the results mean when changing each variable. Can someone give me some info on that? Thanks...(Sorry about the confusing writing:P)

2007-06-02 19:46:54 · 1 answers · asked by dutchychik 2

2007-06-02 19:46:19 · 6 answers · asked by Kila 3

2007-06-02 19:24:24 · 5 answers · asked by naveen s 1

A) are sounded together

B) Have almost the same frequency and are sounded together

C) have the same frequency and are sounded together

D all the above

E) none of the above

2007-06-02 19:17:04 · 5 answers · asked by Anonymous

Wats the cost to collect and refine nuclear power source (uranium)?
cost to transport
cost of equipment to convert into electricy
price to consumers?

2007-06-02 19:06:31 · 5 answers · asked by khanh_kangaroo 1

2007-06-02 18:57:06 · 4 answers · asked by Anonymous

2007-06-02 18:41:01 · 4 answers · asked by Anonymous

why is that visible light can pass through transparent objects but not opaque ones?

2007-06-02 18:26:09 · 6 answers · asked by formystudies6 1

2007-06-02 18:23:16 · 8 answers · asked by cop350zx 5

............/~~\.........
.........../~~~\........
...40>/~~~~\<40
........./__x__\......
......../~~~~~~\.....
60>/~~~~~~~\<60
...../~~~~~~~~\...
..../~~~~~~~~~\..
______ Y_____
Isosolese triangle
60m is how long the side is
40m is how long the side is
therefore one side equals 100 metres
i need to know what size is x and y.

the only thing that was given to me was x+y=80, which obviously means the x side and the y side both add to equal 80

answer:

since both triangles are proportional, we can say that :
40/x = 100/y
40y = 100x
and since x + y =80,
y= 80 - x
then,
40 (80 -x ) = 100 x
3200 - 40x = 100 x
3200 = 140 x
x = 22.857

substitute, x to the first equation,
40/22.857 = 100/y
1.75 = 100/y
y = 57.143



if someone asks me how did i get the answer and why did i end up with that answer, how do i explain it?????????

2007-06-02 18:14:35 · 1 answers · asked by Anonymous

2007-06-02 17:50:51 · 4 answers · asked by Anonymous

2007-06-02 17:48:02 · 4 answers · asked by Anonymous

2007-06-02 17:45:43 · 5 answers · asked by Anonymous

Really.

2007-06-02 17:18:05 · 8 answers · asked by Anonymous

Could stars and planets exist if sub atomic particles were simple indivisible particles with no wave/particle duality and light was a simple wave, or is there some underlying reason why the strageness of quantum mechanics is necessary

2007-06-02 16:51:49 · 3 answers · asked by Anonymous

I have circuit which has parallel capacitors and series capacitors, what I want to know is when a Voltage is applied will I have to take into account those series and parallel capacitors when determining charge? Can I just assume that Q will be the same for one capacitor even though it is in series and parallel with others?

2007-06-02 16:37:44 · 5 answers · asked by Nate-dawg 2

A person was in a disk-shaped vehicle, and the floor spun around? As the vehicle accelerates forward, the disk spins at an RPM equal to that of the rate of acceleration? What effect would the direction of rotation of the disk relative to the motion of the vehicle have on the effect? Would the person's inertia cause him to stick to the wall, be "thrown back", or neither?

I know, this is weird, but I want to know.

2007-06-02 16:32:34 · 3 answers · asked by Michael n 2

2007-06-02 16:28:13 · 3 answers · asked by cindy m 1

2007-06-02 16:27:39 · 8 answers · asked by Anonymous

What if a spacecraft could emit a repetitive alternation of strong magnetic fields (positive, then negative, or vice-versa)
Could the ship actually attract itself and move through space?

2007-06-02 15:53:31 · 6 answers · asked by Michael n 2