# All Questions

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### The total horizontal distance traveled by a bouncing ball nudged off a table of height $H$ [closed]

Suppose a ball gently rolls off a flat surface of height $H$ and free falls to the ground subject only to the law of gravity. Once the ball hits the ground, it rebounds as shown in the figure. When ...
• 101
21 views

### How to count simple resistor circuit configurations? [closed]

Really stumped by this one (I'm not an EE!). Suppose we are given 1, 2, 3, 4, 5, and 6 one-ohm resistors. They can be arranged in series, parallel, bridge, and so forth circuits. No dangling resistors ...
70 views

### Non-crossing approximation (NCA) in 'Large-$N$ expansion' (Altland & Simons CMFT)

I have a question about non-crossing approximation (NCA) stated in Condensed Matter Field Theory by Altland & Simons1. It is on page 200-203 for the 3rd edition (on page 223-227 for the 2nd ...
• 31
36 views

### Isentropic or isenthalpic expansion for the remaining fluid in a previously pressurised tank? [closed]

Imagine a container filled with ammonia at 25 bar and 100 degC. Assume that an orifice is opened, so that fluid can flow through ...
146 views

### QFT with massless particles

EDIT: Often in textbooks one discusses QFT with massless particles, e.g. massless fermions or scalar particles. What mass vanishes: bare or physical? or both?
• 2,226
503 views

### How accurate does the ISS's velocity and altitude need to be to maintain orbit?

We know the the ISS is not drifting weightless in space, but rather is constantly falling as it circles the Earth. To do this it must be at a specific altitude and moving with a specific velocity. ...
• 4,783
1 vote
47 views

### Numerical Solution of the circular restricted three body problem [closed]

I am trying to numerically solve the differential equations in the planar circular restricted three-body problem. In the rotating frame, the differential equations are given by \...
33 views

• 1,131
1 vote