Physics - September 2006

A bicyclist is driving up a hill which is tilted at 8 degrees. How big is the force caused by gravity that "drags" the bicyclist down the hill?

Answer is: 110N

2006-09-20 09:42:27 · 3 answers · asked by - 1

I'm lost....

"The specific heat capacity of copper is 0.092 calories per gram per degree Celsius. How much heat is required to raise the temperature of a 10-gm piece of copper from 0 degrees celsius to 100 degrees celsius? How does this compare with the heat needed to raise the temperature of the same mass of water through the same temperature difference?

2006-09-20 09:23:58 · 2 answers · asked by Anonymous

I'm so lost....how do I go about solving a problem like this?....

"Pounding a nail into wood makes the nail warmer. Consider a 5-gram steel nail 6cm long and a hammer that exerts an average force of 500N on the nail when it is being driven into a piece of wood. The nail becomes hotter. Calculate the increase in the nail's temperature (Assume that the specific heat capacity of steel is 450J/kg*degC)"

2006-09-20 09:14:00 · 5 answers · asked by Anonymous

I understand the bucket of water example, but in space etc there is no bucket.
So where does gravity come from?

2006-09-20 08:53:50 · 20 answers · asked by cragoogle 1

and what is the fastest speed to date

2006-09-20 08:43:03 · 13 answers · asked by Sir_john_Jr 1

:)) i need that information :P

2006-09-20 08:38:56 · 14 answers · asked by Crazy_DIAMOND 3

How are the microwaves coming from the sun generated by pulsed direct current, as opposed to microwave generated by magnetron?

What exact is pulsed direct current?

In order to provide a context for those two questions, they arised from the issue of microwave heating in the reference below under the section Heating Food:
http://www.mercola.com/article/microwave/hazards2.htm

Thanks very much in advance.

2006-09-20 08:29:14 · 3 answers · asked by M 3

Suppose that Galileo is in the Leaning Tower of Pisa. He throws a cannonball straight down from height H above the ground. The ball leaves his hands with an initial speed Vo. At the same instant, his friend throws a cannonball straight up from ground level with an initial speed of 2Vo. When the cannonballs collide, they are traveling in the same direction and Galileo's cannonball is
traveling with 7 times the speed of his friend's. Ignore air resistance.

a. At what time does the collision occur? Express your answer in terms of H and Vo
only.
b. At what height above the ground does the collision occur? Express your answer in terms of H only

2006-09-20 08:26:22 · 1 answers · asked by Anonymous

2006-09-20 08:20:15 · 7 answers · asked by ifoam 3

Why?

2006-09-20 08:14:52 · 11 answers · asked by ifoam 3

2006-09-20 07:17:07 · 3 answers · asked by Avni A 1

2006-09-20 06:46:11 · 11 answers · asked by Anonymous

I'm having problems with the one physics problem. Not sure which equation(s) to use. Anyways, here is the problem:
An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at +43 ft/s2. After some time t1, the rocket engine is shut down and the sled moves with constant velocity v for a time t2. Assume the total distance traveled by the sled is 15950 ft and the total time is 90 s.

I need to find t1, t2, and the velocity.

2006-09-20 06:34:44 · 7 answers · asked by terpjenrose 1

hydroxyl group, carbonalkoxyl group, carbonyl group, carboxyl group. pick one

2006-09-20 06:23:32 · 2 answers · asked by Anonymous

the room temperature is 25 degree celcius, while our body temperature is 37 degree celcius. So, we are hotter than the surroundings.

We have also known that black is a good emitter of heat, as compared to white.

So, when we wear a black shirt, we should be emitting heat faster to the surroundings, as compared to a white shirt, thus making us cool faster. However, it is wearing white shirts which will make us cooler.

What is the flaw in my concept? I've tried to find the answers, but to no avail.

Thanks.

2006-09-20 05:47:56 · 5 answers · asked by Anonymous

Please tell me from where the electricity comes on the water dams?

2006-09-20 05:47:00 · 9 answers · asked by Gordito 1

the horn of a motor car,an ACgenerator, a microphone, a loudspeaker. pick one .

2006-09-20 05:36:02 · 9 answers · asked by Anonymous

(last I checked explosians go in all directions)

why is the space-time continuum always shown as a flat grid?

2006-09-20 05:06:00 · 9 answers · asked by Anonymous

plz give ur answer seriously

2006-09-20 04:31:40 · 9 answers · asked by haruls 1

2006-09-20 03:57:25 · 6 answers · asked by Ajay I 1

show that at any time t, where friction is negligible, the velocity of a projectile (launced at an angle Ө with a speed V1) makes an angle Өt with the horizontal given by the expression

Өt= tan -1=(tan = (gt/v initial cos Ө))
where g<0

really just looking for someone to help walk me through this I have not been able to get ahold of my physics professor the past two days.

2006-09-20 03:38:50 · 2 answers · asked by Anonymous

2006-09-20 02:42:02 · 2 answers · asked by Anonymous

defination used in physics.

2006-09-20 02:31:48 · 13 answers · asked by Anonymous

like example a car runs 15 miles on a litre how do we know it. how do we know what is the power of the car what is the reason behind it . in short what are the calculations behind car mechanics

2006-09-20 02:20:27 · 2 answers · asked by Jaskirat S 1

If I removed the "container" of a glass of water, shouldnt it be possible for the water to still exist molded in that form? like Ice?

Is there a substance, when added to water, will make it stand still vertically, (assume no gravity)

2006-09-20 01:57:03 · 4 answers · asked by Anonymous

Light would presumably not travel fast enough to enter your eye.

2006-09-20 01:56:29 · 14 answers · asked by cassingham 1

2006-09-20 01:34:50 · 1 answers · asked by Hoshiladevi R 1

2006-09-20 01:33:20 · 2 answers · asked by Hoshiladevi R 1

24. (III) A hollow cylindrical resistor with inner radius r1 and outer radius r2, and length l, is made of a material whose resistivity is p (Fig. 25-32). (a) Show that the resistance is given by

R=(p/(2pil)) ln (r2/r1)

for current that flows radially outward. [Hint: Divide the resistor into concentric cylindrical shells and integrate.] (b) Evaluate the resistance R for such a resistor made of carbon whose inner and outer radii are 1.0mm and 1.8mm and whose length is 3.0cm. (c) What is the resistance in part (b) for current flowing parallel to the axis?

2006-09-20 00:10:20 · 1 answers · asked by Anonymous

Would your craft flip up and cartwheel out of control, or would the surrounding water blow up and you'd come through without a scratch? The reason i am asking is that the water speed record is about 450-500 mph, the next phase of this challenge would be to get as close to the sound barrier or even break it.

2006-09-19 23:58:39 · 10 answers · asked by IshotJR 2