Physics - February 2007

2007-02-04 16:46:34 · 8 answers · asked by anil s 1

If both the mass and the velocity of a ball were tripled, the kinetic energy of the ball would increase by a factor of________?
a. 3
b. 6
c. 9
d. 27

Why?

2007-02-04 16:41:08 · 5 answers · asked by ARB 2

If friction is the only force acting on an object during a given physical process, which of the following assumptions can be made in regard to the object's kinetic energy?
a. The kinetic energy decreases
b. The kinetic energy increases
c. The kinetic energy remains constant
d. The kinetic energy decreases and then increases

Why?

2007-02-04 16:38:06 · 7 answers · asked by ARB 2

Don't they both say that an object will remain at constant speed until an external force acts upon it?

2007-02-04 16:36:49 · 3 answers · asked by The Riddler 3

A rocket with a mass of 1.2 x103 kg is scheduled to lift-off from a launch pad with an acceleration of 25 m/s2. What upward force must be externally applied to cause this acceleration?

can someone explain this one to me

2007-02-04 16:36:40 · 3 answers · asked by Dust T 1

THere is an electric field of 3.73 x 10^14 N/C. What is the work needed to move a +0.10 microcoulomb charge from X to an infinite distance away and give it 0.02 J of kinetic energy?

2007-02-04 16:36:17 · 2 answers · asked by john P 1

Assume you have a small robot on wheels, and that it has infinite computing capabilities and infinitely fast processing. You program it to move 6 inches in 30 seconds, and then to repeatedly move 1/2 the previous distance in 1/2 the previous time, therefore going
3 inches in 15 seconds
1.5 inches in 7.5 seconds, etc.
Assuming (due to its infinite memory and speed) that it never experienced any computing errors, then it would never slow down, never stop, but never make it to the 1-foot mark.
What would happen?

2007-02-04 16:12:48 · 5 answers · asked by josef 2

Yoou are driving at 35km/hr when the road desends suddenly 15m into a valley.You take your foot of the accelorator and coast down hill.Just as you reach the bottom you see the police hiding behind the speed limit sighn that reads 70 km/hr.

2007-02-04 15:50:21 · 2 answers · asked by RhondaJo 2

2007-02-04 15:47:50 · 1 answers · asked by Who_am_i 1

Pliz help!! =]

2007-02-04 15:27:15 · 3 answers · asked by Anonymous

Take the mass of the Earth to be 5.98 * 10^24 kg. If the Earth's gravitational force causes a falling 63 kg student to accelerate downward at 9.8m/s^2, determine the upward acceleration of the Earth during the student's fall.

2007-02-04 15:25:32 · 6 answers · asked by krstilyzed 1

Forgive me if I misunderstand, but from what I have heard about Schrodinger's Cat, it is an analogy for how observation effects the outcome of an experiment. However, I still don't know if the example of a cat being both alive and dead effectively describes this. How can something that concerns things on an atomic (and subatomic?) level be compared to matters concerning an extremely complex, multicellular living thing?

Does anyone else have an opinion on this issue? Do you think the analogy works? If so, how/why?

Again, please forgive me if I misunderstand the experiment. I freely admit (though it's probably obvious) that I am not a physicist and probably need more knowledge in this area to completely understand it, but that's exactly why I'm asking about it.

Thanks.

2007-02-04 15:12:22 · 10 answers · asked by Anonymous

I've always wondered why the amount of bullets the main hero can take before dying differs so much, so how many bullets do you think a fit ,am at the prime of his life take? Also how much difference does it really make where it hits?

2007-02-04 15:04:00 · 7 answers · asked by Mr. Jack Dulligan 2

If your traveling at the speed of light and you turn on your headlights can you see ahead of you?

2007-02-04 14:56:37 · 8 answers · asked by Anonymous

2007-02-04 14:34:05 · 7 answers · asked by Icegirl 1

2007-02-04 14:32:05 · 5 answers · asked by Icegirl 1

i have to perform an experiment in which i have tio determine the mass of a stick without a balance. here is the information given: the center of mass of the object is determined by balancing the object on a pivot or fulcrum. a triangular file or something with a thin edge works well for a pivot. the pivot can be supported by 2 cans of beans. mark the center of mass on the object.

Now place the object so that its center of mass is not over the pivot. suspend a known mass from the short end and move the mass until the object balances in a horizontal position.
Since all the mas of the stick can be considered to be at the center of mass, and since the clockwise and counter-clockwise torques are equal, (known weight)(d1)=(weight of stick)(d2)
for a known mass you could use a roll of nickels (20 g) or a peper cup with as many nickels as u want at 5.0 g per nickel.
now can someone please tell me how to setp up this experiment? i dont have anything at home for a pivot any suggestions?

2007-02-04 14:25:52 · 1 answers · asked by Fatima 1

2007-02-04 14:13:33 · 6 answers · asked by boncat8 2

and from this show that (partialE/PartialV)t=a/V^2 for a van der walls gas

2007-02-04 14:10:40 · 1 answers · asked by joy 1

1) what is the e lectric force between a glass ball that has +3.9 mC of charge and a rubber ball that has -5.0mC of charge and a rubber ball that has -5.0 mC of charge when they are separated by a distance of 3.5 cm? The Coulomb constant is 8.98755 x 10^9 N*m(sq)/C(sq). Answer in N.

2) Two electrons in an atom are separated by 1.5 x 10^ -10 m, the typical size of an atom. The Coulomb constant is 9 x 10^9 N*m(sq)/C(sq). What is the force between them? Answer in N.

3) Would you feel any electrical effects if you were inside the charged sphere of a van de Graaff generator? Why or why not?

2007-02-04 14:09:46 · 1 answers · asked by y0sweetz 1

since the inside of a circle travels slower than the outside, if the inside was traveling at just below the speed of light, wouldnt the outside be treaveling faster than light? and the middle at the speed of light?

2007-02-04 14:06:52 · 4 answers · asked by Anonymous

and evaluate this difference for an ideal gas and a gas that obeys the van der Waals equation

2007-02-04 14:02:30 · 1 answers · asked by joy 1

What is the total acceleration in m/s^2 of a bug on the rim of a 8.0 in. diameter disk if the disk moves from rest to an angular speed of 76 revolutions per minute in 5.0 s? And what is the degree(relative to the tangential acceleration)?

I found all of this information out about the problem:
tangential acceleration=.162
tangential velocity=.81192
tangential acceleration=.162
centripetal acceleration=.259

Thanks for helping!!!

2007-02-04 14:00:14 · 1 answers · asked by Tennis2127 2

When opening ice cream for the first time, it is always so easy to scoop. But once returned to the freezer and then used a second time (such as a day later) it is always so much harder. Why is that? There must be some logical explanation. We even did an experiment where we bought ice cream, stored it in the freezer for a day, opened it for the first time and it was soft. However, upon second use (a day later) it was hard...puzzling. Come on scientists; help us out on this one!

2007-02-04 13:56:14 · 5 answers · asked by john_hollykaiser 1

help me

2007-02-04 13:26:43 · 4 answers · asked by Anonymous

2007-02-04 13:20:47 · 6 answers · asked by Anonymous

I need help writing an acrostic poem for any word related to the concept of forces

2007-02-04 13:16:23 · 1 answers · asked by angelonearth3332000 1

Three capacitors (4.0, 6.0, and 8.0 µF) are connected in series across a 50.0-V battery. Find the voltage across the 4.0-µF capacitor.
V

A 3.0 µF capacitor and a 4.0 µF capacitor are connected in series across a 46.0 V battery. A 15.0 µF capacitor is also connected directly across the battery terminals. Find the total charge that the battery delivers to the capacitors.
C

2007-02-04 12:54:48 · 1 answers · asked by Taylor W 1

I have an idea of inventing a machine which will be very helpful for the cardiac patient But I dont know how to go to the second step.
which is the real creation process.pls if any body knows help me

2007-02-04 12:53:46 · 3 answers · asked by Anonymous

2007-02-04 12:46:54 · 4 answers · asked by david w knows best most times if 1