Physics - February 2007

When a bee hover's near a flower's anther, which is electrically insulated, the pollen grains jump to the bee.
Assuming that a bee with a typical charge of 45pC is a spherical conductor, find the magnitude of the bee's electric field at the location of a pollen grain .02m from the bee's center.

2007-02-09 06:50:23 · 1 answers · asked by Make a wish 1

2007-02-09 06:08:24 · 4 answers · asked by ali s 1

Question: the solar wind is a thin, hot gas given off by the sun. charged particles in this gas enter the magnetic field of the earth and can experience a magnetic force. suppose a charged particle traveling with a speed of 9.0e6 m/s encounters the earth's magnitude of 1.2e-7 T. assuming that the particle's velocity is perpendicular to the magnetic field at an altitude where the magnitude of 1.2e-7 T. assuming that the particle's velocity is perpendicular to magnetic field find the radius of...Find (a) an electron and (b) a proton

My Approach:

(a) electron
r = (9.11e-31)(9.0e6)/ (1.6e-19)(1.2e-7) = 427 m

(b) proton
r = (1.67e-27)(9.0e6)/ (1.6e-19)(1.2e-7) = 7.83e5 m

Book Answer: I don't have the answer to (a); however, for part (b) it is supposed to be 7.83e8 m. it's the reason why im posthing this question! appreciate the help

2007-02-09 05:47:03 · 2 answers · asked by Jimmy 3

A driver in a car traveling at a speed of 60 mi/h sees a deer 80 m away on the road. Calculate the minimum constant acceleration that is necessary for the car to stop without hitting the deer (assuming that the deer does not move in the meantime).

2007-02-09 05:37:17 · 5 answers · asked by Anonymous

Question: In a heart pacemaker, a pulse is delivered to the heart 81 times per minute. the capacistor that controls this pulsing rate discharges through a resistance of 1.8e6 ohms. one pulse is delivered every time the fully charged capacitor loses 63.2% of its original charge (CONFUSING!). what is the capacitance of the capacitor?

My Approach:
I went ahead and converted 81 pulses/minute to pulses/second (which is like 1.35 pulses/sec). I am having trouble plugging these numbers into an equation - q = q(initial)*e^(-t/RC). im not sure that's the equation to use. i would appreciate all the help i can get on this problem! even a fully solved problem would be cool.

Book Answer: 4.1e-7 F

2007-02-09 05:33:04 · 3 answers · asked by Jimmy 3

Question: In a heart pacemaker, a pulse is delivered to the heart 81 times per minute. the capacistor that controls this pulsing rate discharges through a resistance of 1.8e6 ohms. one pulse is delivered every time the fully charged capacitor loses 63.2% of its original charge (CONFUSING!). what is the capacitance of the capacitor?

My Approach:
I went ahead and converted 81 pulses/minute to pulses/second (which is like 1.35 pulses/sec). I am having trouble plugging these numbers into an equation - q = q(initial)*e^(-t/RC). im not sure that's the equation to use. i would appreciate all the help i can get on this problem! even a fully solved problem would be cool.

2007-02-09 05:31:31 · 1 answers · asked by Jimmy 3

its something about Harmonic Oscillations. I have find the wt and the ∆wt. but i need to find wm and ∆wm so plzz help me to find out , which formula do i have to use to find.

2007-02-09 05:19:29 · 1 answers · asked by christe_pol 1

2007-02-09 05:08:36 · 6 answers · asked by Matty M 1

physical science that is

2007-02-09 04:57:53 · 2 answers · asked by Anonymous

A uniform wire out of 0.800 g of copper. If the wire is to have a resistance R = 0.500 , and if all of the copper is to be used.
What will be the length of the wire?

2007-02-09 04:43:21 · 2 answers · asked by activegirl 1

2007-02-09 04:37:18 · 5 answers · asked by avani 1

For gravity how do you know when to have 9.81 m/s^2 positive or negative? Thanks.

2007-02-09 04:29:34 · 10 answers · asked by Kacey L 1

A car starts from rest and travels for 5.0 s with a uniform acceleration of +2.7 m/s2. The driver then applies the brakes, causing a uniform acceleration of -3.0 m/s2. If the brakes are applied for 2.0 s, determine each of the following.

(a) How fast is the car going at the end of the braking period?

(b) How far has it gone?

2007-02-09 04:22:54 · 1 answers · asked by Anonymous

What is the total energy of a two body system and how do we get it?

2007-02-09 04:04:05 · 1 answers · asked by Anonymous

I need the unit of Pressure Weight and Force thank you

2007-02-09 03:19:41 · 6 answers · asked by Anonymous

2007-02-09 03:19:00 · 11 answers · asked by lithium20202 1

i no you use s=ut+0.5at(squared) but am not sure wat i do with that equation :P lol

2007-02-09 03:11:38 · 10 answers · asked by lithium20202 1

...and how does a reflector in a nuclear reactor work, i.e. what causes escaping neutrons to return to the reacting mass?

2007-02-09 03:09:17 · 4 answers · asked by QQ dri lu 4

2007-02-09 02:47:35 · 5 answers · asked by Anonymous

2007-02-09 02:12:40 · 8 answers · asked by CLIVE C 3

how does it produce electricity, how does it transform mechanical energy to electrical energy...etc

2007-02-09 02:09:23 · 8 answers · asked by rA_0215 2

I read lot of thread for C shape melectromagnets calculation and i want to know calculation difrence between c shape Electromagnet and following:

I-Top Iron Plate 750 x 75 x 50mm thick
IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
II CC IIIIIIII CC II I-4Side plate of 20mm thick
II CC IIIIIIII CC II
II CC IIIIIIII CC II
! !-270 x 270 x430mm pole
! C-Coil
This magnet have 1.8KW 220V DC and 9.7 Amps. Aluminium wound and how can i calculate the coil which produce 500Gauss at distance of 200mm from magnets face.

2007-02-09 02:01:48 · 1 answers · asked by pjkhatri 1

2007-02-09 01:49:56 · 13 answers · asked by kutty 1

A string 2.50 m long has a mass of 0.00350 kg. Calculate the speed of mechanical waves in this string when it is under a tension of 0.900 N.

2007-02-09 01:36:32 · 1 answers · asked by Kana P 1

2007-02-09 01:03:40 · 13 answers · asked by Anonymous

2007-02-09 00:59:43 · 16 answers · asked by Anonymous

2007-02-09 00:43:33 · 7 answers · asked by SHIKHA G 1

Consider both objects as water, in hard plastic containers. will they reach at the same time or almost at the same time or at diffrent times. need a scientific answer . which formula will be used to calculate?

2007-02-09 00:23:58 · 13 answers · asked by a novice on computers 1

2007-02-09 00:09:23 · 4 answers · asked by Ansherinah_19 1

2007-02-08 23:20:59 · 7 answers · asked by shaikh Mohammad Gani s 1