gravity

B Would it be possible to make something float?

While waiting in the doctor’s office, I looked at a ballon sticker on the wall. That made me think (once again). Would it be possible to make...
Thread by: doglover9754, Jan 10, 2018, 18 replies, in forum: General Physics

B Origin and demonstration of Newton's second law

At highschool, we saw without demonstration the fundamental principle of dynamics (2th Newton's law), i.e : \sum \vec{F}=m...
Thread by: fab13, Dec 22, 2017, 1 replies, in forum: General Physics

B What would happen if you take a piece of a pulsar

Hi, what would happen if you took 1 cubic meter of matter from pulsar into empty space what would happen does the matter will expand since there...
Thread by: johnpro1, Dec 3, 2017, 1 replies, in forum: General Physics

Studying How to learn QFT on curved spacetimes by myself?

I have a major in mathematical physics and mathematics and currently I'm on a graduate course in Physics working on a master's thesis. When I...
Thread by: leo., Dec 1, 2017, 1 replies, in forum: Academic Guidance

B Why do objects fall at the same speed in free fall?

This is something I haven't been able to wrap my head around yet. In physics, I've always been told that gravity is a force that ALWAYS works...
Thread by: Jay Addy, Nov 24, 2017, 30 replies, in forum: General Physics

B Escape velocity and kinetic energy of the Earth

If you had two masses, m_{1} and m_{2}, and you released them in space infinitely far apart, their kinetic energies would satisfy...
Thread by: Alexander350, Nov 5, 2017, 6 replies, in forum: General Physics

B Why a book on a table is not an example of Newton's 3rd law?

In a physics test in a Norwegian website of a school book, it says following: True or false? (1) According to Newton's 3rd Law, the weight of a...
Thread by: Karagoz, Oct 30, 2017, 10 replies, in forum: General Physics

Explaining acceleration due to gravity without math

Hi, I teach a physics class to a group of homeschooled students. Many of them aren't yet at the level of algebra. Last week we went over...
Thread by: Nightowl, Oct 28, 2017, 18 replies, in forum: Educators and Teaching

Expressing y(t) including the effects of air resistance & gravity

1. The problem statement, all variables and given/known data Hi everyone! So I've got this similar problem as I posted yesterday, but this one is...
Thread by: Cooojan, Oct 19, 2017, 7 replies, in forum: Introductory Physics Homework