Physics - October 2007

2007-10-16 07:35:53 · 4 answers · asked by Anonymous

a 45 kg girl is standing on a 150 kg plank. The plank originally at rest, is free to slide on a frozen lake, which is a flat frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.50 m/s to the right relative to the plank.


1. What is her velocity relative to the ice surface?



2. What is the velocity of the plank relative to the ice surface?


Could you please explain this to me, also....I'm lost. THANK YOU.

2007-10-16 07:35:17 · 1 answers · asked by Captain Whiskerboy Litterbox 3

Are there any torches that have the same intensity as sunlight?

2007-10-16 07:33:39 · 6 answers · asked by Buzzard 7

the head of a golf club (200 g) is traveling at 55 m/s just before it strikes a 46 g ball at rest on a tee. After collision, the club head travels in the same direction at 30 m/s.

What is the speed of the ball just after impact?? explain??

2007-10-16 07:31:38 · 2 answers · asked by Captain Whiskerboy Litterbox 3

If two objects collide and one is initially at rest, is it possible for both to be at rest after the collision? Is it possible for one to be at rest after the collision? Why/how???

2007-10-16 07:22:00 · 4 answers · asked by Captain Whiskerboy Litterbox 3

2007-10-16 06:53:21 · 4 answers · asked by Arkesha S 1

2007-10-16 06:04:58 · 17 answers · asked by krishna_leelakrishna 2

This is to find resistivity of constantan. Can anyone tell me where i am going wrong.

Done the experiment at college today.
R=pl/a
p=rl/a so to put my figures in resistance =0.03 per cm cross sectional area = 0.167mm(sq.) and my results are just no where near Constantan (Eureka) 49 × 10-8
Please help is this just error or am i just not getting something.

2007-10-16 05:37:02 · 4 answers · asked by master 2

2- If there is only a peak in the voltage (without any
reputation in time) , is it possible to filter it by
one RC circuit ? if yes how ? how could we define the
frequency in this case ?

2007-10-16 05:36:02 · 4 answers · asked by Anonymous

A 300 turn coil area of 25 cm^2 is placed in an 80 mT magnetic field. If the coil carries a current of 3.3 A, what is the magnitude of the maximum magnetic torque it could experience?

a) 20 N*m
b) 6.0 N*m
c) 0.13 N*m
d) 0.20 N*m
e) 0.060 N*m

please help

2007-10-16 05:09:39 · 2 answers · asked by Anonymous

A velocity selector for ions uses perpendicular electric and magnetic fields. If the electric field used were 800 V/m, what magnetic field would allow the selection of a velocity of 4000 m/s??

a) 0.040 T
b) 0.080 T
c) 0.16 T
d) 0.20 T
e) 0.50 T

2007-10-16 05:06:57 · 2 answers · asked by Anonymous

A series circuit of 12V source of emf, a 2.00 mF capacitor and a 1000 ohms resistor and switch. When the switch is closed, how long does it take for the current to reach one half its maximum value?

a) 0.693 s
b) 1.39 s
c) 2.00 s
d) 1.69 s
e) 0.0250 s

please help, thanks

2007-10-16 05:06:12 · 2 answers · asked by Anonymous

2007-10-16 05:05:39 · 1 answers · asked by Anonymous

2007-10-16 04:50:06 · 4 answers · asked by Padmini Gopalan 4

A small block with mass m rests on a frictionless horizontal tabletop a distance r from a hole in the center of the table (the figure ). A string tied to the small block passes down through the hole, and a larger block with mass M is suspended from the free end of the string. The small block is set into uniform circular motion with radius r and speed v.What must v be if the large block is to remain motionless when released?Express your answer in terms of the variables r,M ,m , and g.

2007-10-16 04:36:49 · 1 answers · asked by Natiphy2007 1

(Answer if you know correctly about it........)

As we know.....................

When an electron moves from one orbit to another a it get wiggled.And emit radiations.................

Now the question is....... How this radiations produce?
What is this radiations?
Is this Energy which it emit in form of radiations?

2007-10-16 04:06:56 · 3 answers · asked by fha_chafzeto 2

2007-10-16 03:53:32 · 3 answers · asked by ilovedstny 1

We're doing an experiment and it's hard to derive the relationship between a metal's density and its ability to conduct heat... Is there such a relationship or does the metal's ability to conduct heat based solely on atomic structure?

2007-10-16 03:49:17 · 3 answers · asked by grnd_brkr17 2

2007-10-16 03:24:59 · 3 answers · asked by Hikari 1

2007-10-16 03:12:18 · 8 answers · asked by jordan j 1

2007-10-16 02:54:21 · 1 answers · asked by Anonymous

If the net force on a body is zero and if it is moving, it will stop , is it true or false? plzzz help

2007-10-16 02:39:35 · 7 answers · asked by Amir 2

Devise and execute a problem solving strategy that will yield a reasonable physical explanation for how a star is able to resist collapsing under its own gravitational attraction

2007-10-16 02:04:08 · 1 answers · asked by ? 1

A) Sensor
B) Feedback Loop
C) Changer
D) Responder
E) Effector

2007-10-16 01:45:11 · 3 answers · asked by Corey w 1

the area between the graph line and the horozontal axis on a(n) ____ - time graph represents the change of velocity of the object in a given time interval

2007-10-16 00:44:31 · 4 answers · asked by inspectorlocohombre 2

A amusement park ride consists of a rotating circular platform 11.8 m in diameter from which 10 kg seats are suspended at the end of 1.18 m massless chains. When the system rotates, the chains make an angle of 38.1 degrees with the vertical. The acceleration of gravity is 9.8 m/s^2.

What is the speed of each seat? Answer in units of m/s.

Picture: http://geocities.com/grouchy187/figure.bmp

[I did this but I aint sure if its done right. Horizontal force equals mg tan of angle. This is balanced with centripetal force so mv^2/r = mg tan (angle).

So v = sqrt of (g*r*tan (angle))
v = 6.733251157 m/s (don't need sig. figures)

So does this look right to anyone else? Thx.]

2007-10-16 00:41:23 · 3 answers · asked by grouchy187 2

2007-10-15 19:38:31 · 2 answers · asked by deepak.dhall 1

I remember asking my science teacher the question that if a magnet is pointed the negitive down and is in the north pole can it be weighted heavier then if its weighted on its opposite side, due to the reason that the magnetic pulls are going to repel each other and I never got an answer

2007-10-15 19:36:59 · 3 answers · asked by Benny13 3

a cable lifts a 1200 kg elevator at a constant velocty for a distance of 35 m. what is the work done by (a) the tension in the cable and (b) the elevators weight

2007-10-15 19:08:13 · 2 answers · asked by smarin1987 2

2007-10-15 19:02:42 · 3 answers · asked by Anonymous