# topic

1. ### Eight minutes, an ordinary topic

Long long ago, I read a report. I still remember that what it said is about as below: “Since light from the Sun needs about eight minutes to reach the Earth, so something happened in the Sun has nothing to do with the Earth within that eight minutes…” Vice versa. Assume the Earth emits a jet...
2. ### Raining, an ordinary topic

When it was raining while I forgot bringing an umbrella with me, I got wet. I often saw that some guys also without an umbrella resorted to a simple method: run...Did they really meet fewer rain drops?
3. ### wavicle: an old topic

Below is a story in a report many years ago: A professor asked a student: why a (moving) glass seems to have no wavicle character? The student answered: because the Duck de Brogile wavelength is too short, people is not easy to perceive it. (λ = h / p, for a glass, p is big enough to render λ...
4. ### Question about charged circular dish-an old topic

A circular dish is charged with an iron rod in the center. When the dish rotates, someone on the ground considers that there is current and generates magnetism and the iron rod becomes a magnet; while someone else standing on the dish considers that there is no current and no magnetism generated...
5. ### tha mass of photon,a topic of both old and new

the mass of a photon ,either the static mass is M0 and the released mass is ∞，or the released mass is hγ and the static mass is zero, (the detailed calculation with Special Relativity omitted),but both are meaningless in physics. If photon has no effective mass, how to explain the Campton...
6. ### Anti matter: a topic of both old and new

In my first thread To Discuss the Gap Between Mathematics and Physics,I introduced the concept of X4 and interpreted the meaning of it. And we should recognized that the first step should be trying to find out what are the states of cosmos represented by the different X4 values. In this thread...
7. ### Is this correct 2 (Different topic)

While waiting for a responce in my earlier post, I looked theough my project one more time and realized that it had anoter big problem. Again I found a formula I'd like to verify, this time with velocity. Velocity^2 = 2 x acceleration x distance Then take the square root of v^2 to get...
8. ### Paper topic

I am writing a physics paper and I'm having trouble getting started. Obviously I'm not looking for ALL of the answers here but some general bullet points to get me going would be greatly appreciated. Here is the topic. Discuss some of the precursor events or ideas that lead to the...
9. ### Which materials are best to learn the basic of "e^jwt"? What topic is it?

Which materials are best to learn the basic of "e^jwt"?What's the name of the topic? Thanks with gratitude.
10. ### [SOLVED] Topic: Newton's third law

A 2.0 kg bowl strikes the stationary ‘jack’, which has a mass of 1.0 kg, during a game of bowls. It is a head-on collision, and the acceleration of the jack is found to be 25 m s−2 north. What is the acceleration of the bowl? I've calculated the answer to be 13 ms ^ -2 north; why does my...
11. ### Topic on Energy, work and power

Hello there! Question: i) A car C of mass 1200kg climbs a hill of length 500m at a constant speed. The hill is inclined at 6 degrees to the horizontal. The driving force is exerted by C's engine has magnitude 1800N. Find the work done against resistance to the motion of C, as it climbs...
12. ### Useful information topic of multiple sources.

Contrary to what other physics forums state. Two equal sound sources that are not in phase will be a 3.01 db increase, some other forums state it must be 6 dB, this only happens if they are in phase. Lets call the sources 80 dB. initially you need to convert the given dB into a power of 10...
13. ### Project topic

i am an undergraduate in a university in nigeria. i need to choose a suitable project topic in a field of physics. any ideas?