# Anika

### iPad Pro has trouble streaming videos at home, but other devices do not.?

Yesterday we got connected to some new and better wifi. Since then, my iPad Pro has had trouble streaming any kind of videos, either they be from YouTube, Netflix, Play Movies, etc... Sometimes the video won’t load and keep buffering. Other times it’ll load with a good quality for a few minutes and then stop and return to buffering. On any other device in the house, be it my phone, pc or my moms IPad Air, the videos will stream perfectly with no buffering and in HD. I’ve tried restarting my iPad, reconnecting to the internet multiple times and even updating it. Nothing seems to work. I still have 200 GB of storage left, so I don’t see that being the issue. Does anyone know what’s going on? Thanks in advance!

Laptops & Notebooks3 months ago### Math based Astronomy Textbook?

I am taking an astronomy course at my university which is heavily math based since I am in a Science program. They ask us a lot of math based questions on assignments but don’t give us a lot of math based questions to do. Do you know of any good math based astronomy textbook or book (preferably not too expensive) that I could use to practice with and that come with answers? I am finding lots of textbooks online but it is hard to determine what questions they ask since they don’t usually give you any previews of the books. Questions should include:

-Orbital radius

-Angular diameter

-Orbital period and semi major axis

-Blackbody radiation

-Light based questions such as wavelength

-Orbital speeds and escape velocities

-Star brightness

-etc

Thanks in advance for the help!

3 AnswersAstronomy & Space11 months ago### Black body radiation question?

The total energy output of the Sun (its “luminosity”) is 3.826 x 10^26 Watts. (a) How much energy is received on one square meter of the surface of Mars when the Sun is directly overhead (Mars is 2.3 x 10^8 km from the Sun)? (b) This 1 meter square area absorbs one-quarter (0.25) of this Solar energy (reflecting or scattering the rest back into space). As a result it heats up until it emits exactly the amount of absorbed energy as infrared light. After that this piece of the surface of Mars is in temperature equilibrium, and stays at a constant temperature, balancing heating from the Sun with cooling by IR emission. If the emission process is that of a blackbody then what is the surface’s equilibrium temperature?

I am stuck on the first part of the question (a). I would appreciate someone showing me the proper steps to take to reach the answer to this question. Thanks in advance!

1 AnswerPhysics11 months ago### Angular Diameter of Mars?

Assuming that both Mars and the Earth have circular orbits how large will Mars appear to be (ie what is its angular diameter?) at Opposition. Assume that the radius of Mars 3,390 km and that its orbital radius is 1.524 AU.

I’ve calculated this using 2arctan(r/D), where r is the radius of mars and D is the distance in kilometres from earth to mars (7,839e7, 1-1.524AU times the AU value in Km). My answer is of 8,649e-5 degrees and 0.3114 arc seconds (8,649e-5 times 3600). However, when I looked up the angular diameter for mars in arc seconds it is between 14.1 - 25.1 arc seconds, making my answer significantly smaller. What have I done wrong?

2 AnswersAstronomy & Space11 months ago### Electric fields?

Charge q1=1.00 nC is at x1=0 and charge q2=3.00 nC is at x2= 2.00 m. At what point between the two charges is the electric field equal to zero?

Could someone please help me out with the steps to solving this problem?

2 AnswersPhysics1 year ago