Physics - May 2007

A horse can exert a horizontal force of 3.5 x 104 N on a rope that passes over a pulley to lift loads vertically. What is the acceleration of a load of weight:

3.5 x 104 N? (Neglect the masses of the rope and pulley)
3.0 x 104 N? (Neglect the masses of the rope and pulley)

2007-05-01 07:25:20 · 1 answers · asked by keith c 1

When the body requires an increased blood flow in a particular organ or muscle, it can accomodate this by increasing the radius of arterioles in that area. What percentage increase in the radius of an arteriole is required to double the flow rate of the blood, all other factors remaining the same?

15.9%
18.9%
41.4%
82.8%
159%


I know that the correct answer is 18.9% but I am not sure how to rationalize this. Can someone explain the logic behind this?
Thank you!

2007-05-01 07:07:43 · 3 answers · asked by Anonymous

A. boosting the energy output of a circuit
B. increasing the current in a resistor
C. smoothing pulsed current
D. switching dc to ac in a circuit
E. increasing or decreasing voltage

2007-05-01 06:51:52 · 8 answers · asked by Bo-Gotti 1

2007-05-01 06:44:59 · 7 answers · asked by scott w 1

OK, we all know that astronaults in orbit experience weightlessness because they are in free-fall, not because of their distance from the earth. Here's my question: What if you were not in a free-fall. Let's say that you were standing on a little platform which was resting on the ground in your back yard. Now, imagine that the platform rises slowly like an elevator. OK, now you are 20 miles up, standing on your platform which is hovering. You are still experiencing 1 G.
Let's slowly increase it's altitude in 20 mile increments, pausing each 20 miles. What gravitational effect would you notice at 60 miles up? (Did I remind you to wear your spacesuit?) How about 160 miles up? 10,000 miles up?
At what point to you effectively experience weightlessness??

2007-05-01 06:33:13 · 7 answers · asked by quantum saphire 2

2007-05-01 06:20:20 · 1 answers · asked by livefast_dieyoung 2

Huge number of Galaxy exploration spaceships was launched
from the Earth, all of them in the plane of the Galaxy.

Except from those ships, which travel ahead of others on the
frontier, each ship X has exactly 7 nearest spaceships, all seven
at the same distance from X as wieved by the captain of X.

What is relative speed v of all 7 closest spaceships
with respect to X?

2007-05-01 06:17:30 · 3 answers · asked by Alexander 6

exert on the car?

2007-05-01 06:06:44 · 2 answers · asked by Ravhnt 1

You have collected exactly 2900 alumininum cans for recycling, each with a mass of 14.2g.
How much energy is needed to melt them if their initial temperature is 25.4 C? Assume the specific heat, the latent heat and the melting point of aluminum are 899 J/kgC, 3.97X10^5 J/kg, and 660.4C respectively. Answer in units of J.

2007-05-01 05:48:16 · 1 answers · asked by papaya 1

2007-05-01 05:45:40 · 11 answers · asked by Regina S 1

2007-05-01 05:44:23 · 5 answers · asked by carboncruncher 2

i have to give a fourteen minute speech on it tomorrow to a bunch of sophomores in high school. i have an advanced knowledge, but i need help dumbing it down...

2007-05-01 05:30:01 · 4 answers · asked by Anonymous

but yet you feel a pull from the earth?

2007-05-01 05:11:05 · 5 answers · asked by stayin alive 2

2007-05-01 05:09:35 · 2 answers · asked by stayin alive 2

if mass 2 is replaced by a third mass which is 200 times greater than mass 2 what will be the gravitational force between mass 1 and mass 3?
also- if mass 1 and 3 are sperated to 10.0 m apart what would be the gravitational force?

2007-05-01 05:06:31 · 1 answers · asked by stayin alive 2

2007-05-01 05:01:50 · 3 answers · asked by stayin alive 2

2007-05-01 03:58:42 · 2 answers · asked by Dre B 1

What is the average power consumption in watts of an appliance that uses 0.75kwh of energy in 1day?
with computations pls

2007-05-01 03:24:12 · 6 answers · asked by szhieru 1

What would be the effect of ignoring the thermometer and stirrer on the calculated specific heat capacity?

2007-05-01 02:48:55 · 3 answers · asked by pristane 1

2007-05-01 01:55:37 · 3 answers · asked by Anonymous

Mayan Calander ends on the 21st Dec 2012 A.D.

if anyone is interested in it then read my blog at http://360.yahoo.com/brodya_89

Does anyone have anymore info on this?

2007-05-01 01:16:44 · 5 answers · asked by Brody 3

I know that resistors oppose the flow of current, so why dont they also lower voltage since current is proportional to voltage? why is there a high voltage when resistance is high as in potential divider?

2007-05-01 00:53:00 · 4 answers · asked by jazmeen 2