Physics - January 2007

Why is it that when I spin my cup of hot chocolate round to get a blob of cream towards my mouth, the hot chocolate does not spin round with the cup? The cup spins but the liquid inside doesn't seem to move inside it. Why is this?

2007-01-29 09:23:18 · 6 answers · asked by dnbgrrly 2

People talk about powering spacecraft with "anti-gravity" drives. But if they are traveling in empty space, where mass is minimal, wouldn't the drive malfunction? My understanding is that gravity only exists in the presence of massive objects, like the Earth, stars and planets. The "universal gravitation field" is incredibly weak. You can overcome it by flipping a penny into the air. So how could "anti-gravity" work as a space drive? Makes no sense to me.

2007-01-29 09:12:34 · 3 answers · asked by Anonymous

Thanks for your extra bit o' incredible detail...Sincereley,Tom Science 4

2007-01-29 09:06:10 · 6 answers · asked by Anonymous

A 100-kg box is pushed across the floor a distance of 40m at a constant velocity. How much heat is developed?
A. 24.5J
B. 1020J
C. 4000J
D. 39,200J
Please help!!!

2007-01-29 08:53:34 · 6 answers · asked by zginder 3

Is it for "decoration", or do they have an aerodynamic effect?

2007-01-29 08:15:51 · 7 answers · asked by comedycatalyst 2

2007-01-29 08:11:13 · 4 answers · asked by Notre1Dame 2

I ate a hideous amount of popcorn yesterday while watching Babel and it made me wonder.

2007-01-29 08:00:00 · 9 answers · asked by toothybaboon 1

I have a lab write up due tomorrow but I can't figure out the correct angle for the magnitude or vise versa. We had to set up a machine that if you were to get the resultant vector correct, all the weights on the other vectors would reach an equilibrium with the resultant. I'm sure I got the magnitude correct because the weights evened out but the angle the magnitude suggests is incorrect. Here's the problem:

A force of 500g at 60 degrees, a force of 400g at 150 degrees, and a force of 300g at 250 degrees.

I need to find the resultant for that. Any help would be great!

2007-01-29 07:57:15 · 3 answers · asked by Anonymous

An airplane is flying horizontally at 200 m/s, and it drops a care package to some people on the ground below. If the package takes 5 seconds to hit the ground, how high above the ground is the plane flying? Also what is the speed of the package when it hits the ground?

2007-01-29 07:07:26 · 5 answers · asked by GSU 1

If car A is traveling at 50 km/hr at an angle of 10 degrees east of north and car B is traveling at 70 km/hr at an angle of 30 degrees south of east, what is the velocity of car A at seen by car B?

2007-01-29 07:04:23 · 1 answers · asked by GSU 1

If Evil Kneival drives his motorcycle up a ramp (inclined 30 degrees above the horizotal) and sails over 10 buses (spanning 36 meters) and lands on a similar ramp, what was his speed at the top of the ramp (either one)?

2007-01-29 07:03:30 · 1 answers · asked by GSU 1

I go out for a walk. I first walk 1km north, then I walk 2 km west. Then I walk northwest ( an angle exactly between north and west) for 2 km. What is my displacement (magnitude and direction (direction means find the angle))? If I did this walk in 2 hours, what is my average velocity (magnitude) in meters per second?

2007-01-29 07:01:19 · 2 answers · asked by GSU 1

Let's make the assumption that time travel will be possible, for the moment. When it is, why hasn't anyone gone back in time to do something as little as asking someone out to something as big as stopping World War II? This world could be a better place if time travel is used for good. Even so, its use in the future causes us to think if the people around us could be from the future.
Also, time travel could take away from the value of decision-making and gives us a "second way out." What's your take on this?

2007-01-29 06:57:17 · 11 answers · asked by soccergamer92 1

2007-01-29 06:39:34 · 3 answers · asked by Hey ;) 3

THE density f copper wire is 8.96g/cm cubed answer has to be in cm cubed

2007-01-29 06:18:30 · 5 answers · asked by Hey ;) 3

If you are travelling in a spaceship travelling with speed comparable to speed of light, then to a stationary person outside the spaceship, time appears to slow down in the spaceship. What would appear to a person (you) when you are looking out of the spaceship at the stationary world? Will time of the outside stationary world even slow down for the person moving with speed comparable to speed of light?

2007-01-29 06:12:59 · 2 answers · asked by Isha K. 2

background knowledge ,
use of physics, like gravity or pressure .....................

2007-01-29 06:11:41 · 1 answers · asked by Anonymous

2007-01-29 06:01:45 · 5 answers · asked by withfilm 1

2007-01-29 06:00:16 · 8 answers · asked by IshotJR 2

2007-01-29 05:57:04 · 5 answers · asked by nalatwolf 1

2007-01-29 05:50:32 · 15 answers · asked by Kim F 2

2007-01-29 05:04:47 · 6 answers · asked by PearL 4

2007-01-29 04:55:41 · 3 answers · asked by Kurt 2

I have vector A = 160 grams at 18 degrees north of east; what is A's component in the East Direction?

2007-01-29 04:53:10 · 4 answers · asked by Anonymous

I am doing a project on the resistance of a wire. I need to know what the p.d is, what you use to measure it, and its unit.

2007-01-29 04:43:31 · 6 answers · asked by jdratbull 2

Saying that there were such things.... What would happen when an unstoppable force, met an immovable object?

2007-01-29 04:38:19 · 10 answers · asked by Anonymous

2007-01-29 04:34:59 · 3 answers · asked by Viswanathan M 1

Home-school student with difficulty figuring the mathmatic equations that apply to physics. The equations for speed, velocity, and acceleration. I have been given scenerios, and need to figure the equation, but I am having trouble coming up with the right figures for the equation.

2007-01-29 04:34:37 · 2 answers · asked by hairraiser02 5

Ok I understand most things about Big Bang but... here are some ruff questions about it.

1. What type of phenomenon is a singularity?
2. How is it possible that so much energy could be contained in such a small source of matter?
3. Newton's First Law of motion indicates that a object at rest will stay at rest unless acted upon by an outside force. If there was only that singularity in the entire universe, what caused the catastrophic reaction that resulted in well... us?

2007-01-29 04:30:14 · 3 answers · asked by purebloodedheinz57 2

If so, what would the difference be say if a person had a vertical of two feet at the north pole?

2007-01-29 04:28:25 · 3 answers · asked by John W 1